1979 Toro Snowblower 524 no spark
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1979 Toro Snowblower 524 no spark
Hi all -- new to the forum.
I was just given a Toro Snowblower 524 (Model 38040) -- made in 1979 according to the Toro web site, based on the serial number. The previous owner said it started dying on him when he was using it, and he just gave up and bought a new one.
Clearly it has a dirty carburetor which will need attention. But in the meantime, I tried starting with a squirt of gas in the cylinder, and got nothing. There's no spark when I ground the spark plug against the block. I put a multimeter on the spark wire and the block, and got a little bit of a jump on the needle when I yanked the cord, but not much. I tried the spark plug in my lawnmower (same plug), and it works fine there.
I've read a number of posts here and found references to disconnecting the kill wire from the coil as a test, but I'm not sure where the kill wire is. In the meantime, I've removed the flywheel to get access to the points and condenser. I've removed them to take to a shop for replacements, but the truth is, they look pretty new. The points are a bit burned, but don't seem that bad to me.
I'm wondering about the coil, and how to test it, or test the mag. There's a horseshoe-shaped iron bracketing the coil, and I'm wondering if it's supposed to be a magnet. (It shows no magnetism at all. It's also really rusted.) I've seen advice here about cleaning the rust off the magnets on the flywheel, but I didn't see anything that looked like magnets on the flywheel. Would that apply to an engine old enough to have points and a condenser?
Suggestions?
Thanks.
I was just given a Toro Snowblower 524 (Model 38040) -- made in 1979 according to the Toro web site, based on the serial number. The previous owner said it started dying on him when he was using it, and he just gave up and bought a new one.
Clearly it has a dirty carburetor which will need attention. But in the meantime, I tried starting with a squirt of gas in the cylinder, and got nothing. There's no spark when I ground the spark plug against the block. I put a multimeter on the spark wire and the block, and got a little bit of a jump on the needle when I yanked the cord, but not much. I tried the spark plug in my lawnmower (same plug), and it works fine there.
I've read a number of posts here and found references to disconnecting the kill wire from the coil as a test, but I'm not sure where the kill wire is. In the meantime, I've removed the flywheel to get access to the points and condenser. I've removed them to take to a shop for replacements, but the truth is, they look pretty new. The points are a bit burned, but don't seem that bad to me.
I'm wondering about the coil, and how to test it, or test the mag. There's a horseshoe-shaped iron bracketing the coil, and I'm wondering if it's supposed to be a magnet. (It shows no magnetism at all. It's also really rusted.) I've seen advice here about cleaning the rust off the magnets on the flywheel, but I didn't see anything that looked like magnets on the flywheel. Would that apply to an engine old enough to have points and a condenser?
Suggestions?
Thanks.
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Okay, forget what I said about the magnets. I just went back out to the garage and looked again--and yes, there are magnets inside the flywheel. And this time, on the piece holding the coil (the stator, according to a Toro parts diagram), I felt a bit of magnetism, not as much as on the flywheel magnets.
So where does that leave me?
So where does that leave me?
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If you have a stator you must have an electric start? The ignition, based on what you're describing is the armature (the little horseshoe job), the points and condenser. From the armature you should have three wires - one high tension lead for the spark plug, one wire going to the points, and one wire for the kill (which is a grounding wire).
If you disconnect the grounding wire (kill wire) you only have the armature/points/condenser left in the ignition system. If you properly ground a good plug and attach the lead to it, and with an armature(well grounded) to flywheel gap of about .010, with clean points (gapped to about .020) and finally a good condenser you should get a spark when you spin the flywheel.
If you don't and the points look clean and gapped about right, there is a pretty good chance the coil is bad.
If you replace the coil and get the spark, you will still need the correct gap on the points for that engine, because that determines the timing of the spark in the ignition system.
If you post back the engine numbers we should be able to come up with that for you.
If you disconnect the grounding wire (kill wire) you only have the armature/points/condenser left in the ignition system. If you properly ground a good plug and attach the lead to it, and with an armature(well grounded) to flywheel gap of about .010, with clean points (gapped to about .020) and finally a good condenser you should get a spark when you spin the flywheel.
If you don't and the points look clean and gapped about right, there is a pretty good chance the coil is bad.
If you replace the coil and get the spark, you will still need the correct gap on the points for that engine, because that determines the timing of the spark in the ignition system.
If you post back the engine numbers we should be able to come up with that for you.
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If you have a stator you must have an electric start? The ignition, based on what you're describing is the armature (the little horseshoe job), the points and condenser. From the armature you should have three wires - one high tension lead for the spark plug, one wire going to the points, and one wire for the kill (which is a grounding wire).
If you disconnect the grounding wire (kill wire) you only have the armature/points/condenser left in the ignition system. If you properly ground a good plug and attach the lead to it, and with an armature(well grounded) to flywheel gap of about .010, with clean points (gapped to about .020) and finally a good condenser you should get a spark when you spin the flywheel.
If you don't and the points look clean and gapped about right, there is a pretty good chance the coil is bad.
If you replace the coil and get the spark, you will still need the correct gap on the points for that engine, because that determines the timing of the spark in the ignition system.
If you post back the engine numbers we should be able to come up with that for you.
If you disconnect the grounding wire (kill wire) you only have the armature/points/condenser left in the ignition system. If you properly ground a good plug and attach the lead to it, and with an armature(well grounded) to flywheel gap of about .010, with clean points (gapped to about .020) and finally a good condenser you should get a spark when you spin the flywheel.
If you don't and the points look clean and gapped about right, there is a pretty good chance the coil is bad.
If you replace the coil and get the spark, you will still need the correct gap on the points for that engine, because that determines the timing of the spark in the ignition system.
If you post back the engine numbers we should be able to come up with that for you.
I won't be able to buy points and condenser until Monday. (And hope I can find the feeler gauge I used to own for my car, way back when.) But how am I supposed to measure a flywheel gap of .01 when the adjustment is made inside the flywheel? I assume this refers to the distance between the inside of the flywheel magnets and the ends of the stator/horseshoe? (I thought the adjustable screws for the stator assembly were how you set the timing.)
I saw elsewhere someone talking about using a file card as a feeler for .01" but I still don't understand the procedure.
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This must be a little different setup than what I'm thinking. Can you post the engine model and serial numbers so we can get on the same page?
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(!$%^$. Is there some way to upload images here from one's computer without having to put it up on a web server first?)
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I think I have the one you're looking at. It's a Tecumseh engine. The mag armature is what they're referring to as the stator.
The timing is by the point gap with the rider on the cam measured at the peak of the cam when the engine is on the compression stroke.
The .010 mag/armature/stator gap using a business card typically refers to a setup with the horseshoe jobby mounted on the outside of the flywheel and the magnets interface with the armature from the outside of the flywheel. When they do that they simply put a business card (which is about .010) between the flywheel and the horseshoe thingy, turn the magnets until they are under the pickups and release the adjustment screws. The magnets pull the pickups down to them, you tight the screws and turn the flywheel to get the magnets away from the pickups and pull out the card.
You may be able to use that basic procedure to do that engine air gap. I haven't been into that particular engine. I'm sure Cheese or some of the other pros here have a trick for doing it.
The timing is by the point gap with the rider on the cam measured at the peak of the cam when the engine is on the compression stroke.
The .010 mag/armature/stator gap using a business card typically refers to a setup with the horseshoe jobby mounted on the outside of the flywheel and the magnets interface with the armature from the outside of the flywheel. When they do that they simply put a business card (which is about .010) between the flywheel and the horseshoe thingy, turn the magnets until they are under the pickups and release the adjustment screws. The magnets pull the pickups down to them, you tight the screws and turn the flywheel to get the magnets away from the pickups and pull out the card.
You may be able to use that basic procedure to do that engine air gap. I haven't been into that particular engine. I'm sure Cheese or some of the other pros here have a trick for doing it.
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I think I have the one you're looking at. It's a Tecumseh engine. The mag armature is what they're referring to as the stator.
The timing is by the point gap with the rider on the cam measured at the peak of the cam when the engine is on the compression stroke.
The .010 mag/armature/stator gap using a business card typically refers to a setup with the horseshoe jobby mounted on the outside of the flywheel and the magnets interface with the armature from the outside of the flywheel. When they do that they simply put a business card (which is about .010) between the flywheel and the horseshoe thingy, turn the magnets until they are under the pickups and release the adjustment screws. The magnets pull the pickups down to them, you tight the screws and turn the flywheel to get the magnets away from the pickups and pull out the card.
You may be able to use that basic procedure to do that engine air gap. I haven't been into that particular engine. I'm sure Cheese or some of the other pros here have a trick for doing it.
The timing is by the point gap with the rider on the cam measured at the peak of the cam when the engine is on the compression stroke.
The .010 mag/armature/stator gap using a business card typically refers to a setup with the horseshoe jobby mounted on the outside of the flywheel and the magnets interface with the armature from the outside of the flywheel. When they do that they simply put a business card (which is about .010) between the flywheel and the horseshoe thingy, turn the magnets until they are under the pickups and release the adjustment screws. The magnets pull the pickups down to them, you tight the screws and turn the flywheel to get the magnets away from the pickups and pull out the card.
You may be able to use that basic procedure to do that engine air gap. I haven't been into that particular engine. I'm sure Cheese or some of the other pros here have a trick for doing it.
Tecumseh Model No. Hs50-67074b (5 H.p. Snowthrower Model No. 38040)
Now I understand why I was so mystified about the instructions for the .01 gap. Yes, I can see how that would be straightforward with the armature on the outside. More difficult with it on the inside.
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That is indeed the correct engine model.
Also, the point gap of .20 is etched in the cover to the points assembly.
Couldn't tinker with it today, though--rain all day.
Also, the point gap of .20 is etched in the cover to the points assembly.
Couldn't tinker with it today, though--rain all day.
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Toro 524
Have you checked all the linkages before you disasembled? Also if the carterator needed cleaning it is a possiblility that the passages from the tank are clogged.
As for the spark, Check the wiring carefully. There is a possibility of some broken insulation resulting in improper grounding.
I have the EXACT blower (different serial # ) and once had the same problem. My remedy was a broken connection where the plug and wire met INSIDE the boot. Random disconnection caused by the vibration would stop the engine.
Also invest in a RPM/hour indicator that will mount on the control panel. I put one on and helps to set RPM and track hours for oil changes. Cost about $20. Beer 4U2
As for the spark, Check the wiring carefully. There is a possibility of some broken insulation resulting in improper grounding.
I have the EXACT blower (different serial # ) and once had the same problem. My remedy was a broken connection where the plug and wire met INSIDE the boot. Random disconnection caused by the vibration would stop the engine.
Also invest in a RPM/hour indicator that will mount on the control panel. I put one on and helps to set RPM and track hours for oil changes. Cost about $20. Beer 4U2
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Have you checked all the linkages before you disasembled? Also if the carterator needed cleaning it is a possiblility that the passages from the tank are clogged.
As for the spark, Check the wiring carefully. There is a possibility of some broken insulation resulting in improper grounding.
I have the EXACT blower (different serial # ) and once had the same problem. My remedy was a broken connection where the plug and wire met INSIDE the boot. Random disconnection caused by the vibration would stop the engine.
Also invest in a RPM/hour indicator that will mount on the control panel. I put one on and helps to set RPM and track hours for oil changes. Cost about $20. Beer 4U2
As for the spark, Check the wiring carefully. There is a possibility of some broken insulation resulting in improper grounding.
I have the EXACT blower (different serial # ) and once had the same problem. My remedy was a broken connection where the plug and wire met INSIDE the boot. Random disconnection caused by the vibration would stop the engine.
Also invest in a RPM/hour indicator that will mount on the control panel. I put one on and helps to set RPM and track hours for oil changes. Cost about $20. Beer 4U2
If it ever stops raining here, I'll do a more thorough check of the wiring, though I did look once and didn't see any frayed insulation.
The truth is, I don't fully understand the kill-switch/grounding safety interlocks. I know that you close a circuit (to ground, I guess) to stop the engine, and that that somehow grounds the coil. But I can't quite picture how. One lead from the coil seems to go to ground already.
Interesting that you have the same machine. How did you discover the bad connection in your spark plug wire? Did you have to replace the coil in order to replace that wire? It seems to be all one unit.
As for the carb, I'm leaving that to worry about until after I know I've got a spark.
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Have you checked all the linkages before you disasembled? Also if the carterator needed cleaning it is a possiblility that the passages from the tank are clogged.
As for the spark, Check the wiring carefully. There is a possibility of some broken insulation resulting in improper grounding.
I have the EXACT blower (different serial # ) and once had the same problem. My remedy was a broken connection where the plug and wire met INSIDE the boot. Random disconnection caused by the vibration would stop the engine.
Also invest in a RPM/hour indicator that will mount on the control panel. I put one on and helps to set RPM and track hours for oil changes. Cost about $20. Beer 4U2
As for the spark, Check the wiring carefully. There is a possibility of some broken insulation resulting in improper grounding.
I have the EXACT blower (different serial # ) and once had the same problem. My remedy was a broken connection where the plug and wire met INSIDE the boot. Random disconnection caused by the vibration would stop the engine.
Also invest in a RPM/hour indicator that will mount on the control panel. I put one on and helps to set RPM and track hours for oil changes. Cost about $20. Beer 4U2
If it ever stops raining here, I'll do a more thorough check of the wiring, though I did look once and didn't see any frayed insulation.
The truth is, I don't fully understand the kill-switch/grounding safety interlocks. I know that you close a circuit (to ground, I guess) to stop the engine, and that that somehow grounds the coil. But I can't quite picture how. One lead from the coil seems to go to ground already.
Interesting that you have the same machine. How did you discover the bad connection in your spark plug wire? Did you have to replace the coil in order to replace that wire? It seems to be all one unit.
As for the carb, I'm leaving that to worry about until after I know I've got a spark.
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524 toro
Actually in finding that break I was a little lucky. After I managed to get it started I ran a grounded probe very slowly down the wire. This showed no breaks I then slightly bent the wire at the top of the boot and it stopped. When I pulled the boot back (very had to do by the way) I found that the connection was not to great. I used a repair kit similar to putting generic sparkplug wires on a car and slid the boot back down. It works perfectly. Mine is the original coil by the way.
Also, you mentioned rust. Rust can act like a insulator and intefere with function. Take some emery cloth ( or similar) and gently wipe the face of the horseshoe armature. That may help also.
Again, these worked for me. The only thing I have replaced so far is the auger drive ( thanks to a stick in a snowbank) and a add-on electric starter motor
BTW; The linages I refered to are from the control handles down to the levers at the machine that control speed/drive/auger.
When you start it do not hold any engagement handles. There used to be a on-line maual for the machine but I have a book so never book-marked it, sorrry. But a suggestion is try a local repair shop. Some may have a old book they will give/sell you. In addition try the local library.
Also, you mentioned rust. Rust can act like a insulator and intefere with function. Take some emery cloth ( or similar) and gently wipe the face of the horseshoe armature. That may help also.
Again, these worked for me. The only thing I have replaced so far is the auger drive ( thanks to a stick in a snowbank) and a add-on electric starter motor
BTW; The linages I refered to are from the control handles down to the levers at the machine that control speed/drive/auger.
When you start it do not hold any engagement handles. There used to be a on-line maual for the machine but I have a book so never book-marked it, sorrry. But a suggestion is try a local repair shop. Some may have a old book they will give/sell you. In addition try the local library.
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Toro has the manuals available by reprint from microfiche, so I suppose I'll order one. (I wanted to see if the machine was worth it before I did that, though.)
I'd love it if someone would explain to me how the grounding kill-switch system works. I understand that the idea is that you're grounding the coil, but I can't picture the circuit.
I'll clean the armature and the magnets and see if that helps. I kinda wish I hadn't taken off the points and condenser now, because they look pretty new, and I can't find my feeler gauge. Guess I need to buy a new one. You just set the points with them open at the high point of the cam, right?
I'd love it if someone would explain to me how the grounding kill-switch system works. I understand that the idea is that you're grounding the coil, but I can't picture the circuit.
I'll clean the armature and the magnets and see if that helps. I kinda wish I hadn't taken off the points and condenser now, because they look pretty new, and I can't find my feeler gauge. Guess I need to buy a new one. You just set the points with them open at the high point of the cam, right?
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Go to your local library and get a book on small engine repair. Many libraries have them in their reference section and copy what you may need. I may be wrong ( worked on old vw's) but the tickness of a matchbook cover used to work.
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With the key on and machine in neutral you should have spark. The handle on your right needs to be held when the machine is out of neutral and the auger is engaged. This keeps the operator behind the machine when augers are turning. Yes you set points at the highest point. Even new points should be cleaned. I take 2 strips of lint free paper and with points closed Spray 1 with carb cleaner and pull through the contacts (need to pry open) and then pull the dry strip through.
If you have no spark on an old tecumseh, it is most likely the points. You do not need to set gap between coil and flywheel but you need to set gap on points, they must be clean and the timing needs to be PRECISE. this is done by rotating stator so if you have removed stator this must be done. You either need a dial indicator, or you need to remove the head to do, as piston needs to be .035 BTDC. If you PM with your email address I will forward you a Tecumseh L head manual which explains the procedure. Many techs struggle with timing older Tecumsehs, I have done hundreds and when done correctly the engines start effortlessly. Points are PN# 30547A, condenser is PN#30548B. For the record I would start with a good rebuild of the carb to be sure all is well there 1st.
If you have no spark on an old tecumseh, it is most likely the points. You do not need to set gap between coil and flywheel but you need to set gap on points, they must be clean and the timing needs to be PRECISE. this is done by rotating stator so if you have removed stator this must be done. You either need a dial indicator, or you need to remove the head to do, as piston needs to be .035 BTDC. If you PM with your email address I will forward you a Tecumseh L head manual which explains the procedure. Many techs struggle with timing older Tecumsehs, I have done hundreds and when done correctly the engines start effortlessly. Points are PN# 30547A, condenser is PN#30548B. For the record I would start with a good rebuild of the carb to be sure all is well there 1st.
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If you have no spark on an old tecumseh, it is most likely the points. You do not need to set gap between coil and flywheel but you need to set gap on points, they must be clean and the timing needs to be PRECISE. this is done by rotating stator so if you have removed stator this must be done. You either need a dial indicator, or you need to remove the head to do, as piston needs to be .035 BTDC. If you PM with your email address I will forward you a Tecumseh L head manual which explains the procedure.
I have not removed or loosened the stator assembly (what others here have called the armature, but the manual calls the stator), just the points and condenser. So I can adjust the point gap. I don't know if the chances are good or bad that the timing will be already locked down correctly.
(I don't have a dial indicator for checking the timing. I read on a thread somewhere that you can make the timing adjustment by using a narrow ruler inserted through the spark plug hole, to find TDC and then back off to the correct point. Is that doable?)
Many techs struggle with timing older Tecumsehs, I have done hundreds and when done correctly the engines start effortlessly. Points are PN# 30547A, condenser is PN#30548B. For the record I would start with a good rebuild of the carb to be sure all is well there 1st.
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Hm. I was hoping not to take the head off, partly because I don't have a torque wrench to properly tighten the bolts back. But I just realized that I seem to have removed half the head bolts just to get to where I am now.
How important is it to use a torque wrench, as opposed to "feels pretty tight," when replacing those bolts? (Or the flywheel nut.) Have I reached a point that I should break down and buy a torque wrench?
How important is it to use a torque wrench, as opposed to "feels pretty tight," when replacing those bolts? (Or the flywheel nut.) Have I reached a point that I should break down and buy a torque wrench?
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Prolly varying opinions but I rarely break out the torque wrench unless its internal or bearing/bushing etc. is involved and more critical.
The flywheel nut you want tight, if you have an impact hammer it pretty good, if not but you have a way to hold the crank from turning without breaking anything, use a 1/2" drive and reef on it pretty good.
The head, if you have half the bolts and one side or corner is loose, you would be just as well off to pull it and have a peak and maybe clean it up, check the gasket, replace if questionable at all. More important I think is sequencing the bolts starting with the most center and working out (generally) Prolly off with this guess but for some reason 10-15 ft lbs...? or good and snug with a 3/8" drive ratchet.
I haven't had my elbow sent to the standards lab in years but it seems to still be fairly closely calibrated yet
If you found a manual, it should give you the sequence and torque specs, or no doubt one of the other fine folks here know or have them.
Again this is my practice and may not be the best advice, main thing I try to keep in mind is you do not want to BREAK a bolt or PART by over tightening it.
The flywheel nut you want tight, if you have an impact hammer it pretty good, if not but you have a way to hold the crank from turning without breaking anything, use a 1/2" drive and reef on it pretty good.
The head, if you have half the bolts and one side or corner is loose, you would be just as well off to pull it and have a peak and maybe clean it up, check the gasket, replace if questionable at all. More important I think is sequencing the bolts starting with the most center and working out (generally) Prolly off with this guess but for some reason 10-15 ft lbs...? or good and snug with a 3/8" drive ratchet.
I haven't had my elbow sent to the standards lab in years but it seems to still be fairly closely calibrated yet
If you found a manual, it should give you the sequence and torque specs, or no doubt one of the other fine folks here know or have them.
Again this is my practice and may not be the best advice, main thing I try to keep in mind is you do not want to BREAK a bolt or PART by over tightening it.
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If you have not losened the bolts on the stator, timing may be OK. I understand about the getting spark before tackling carb. Put the points in, set gap and clean even if new. There should be a plate below carb where all wires meet. If you disconnect the one that comes from stator, you will by pass all kill switches and you should have spark. you can then connect and trouble shoot safeties, they may be fine.
you may not be taking head off but to answer question it is best to use a torque wrench, head bolts are 16.5 ft/lb. My suggestion without a torque wrench is to use a 1/4 wratchet with a 1/2" socket the reason is you will not have a lot of leverage and thus less likely to strip. The pattern as mention previously is in the manual.
you may not be taking head off but to answer question it is best to use a torque wrench, head bolts are 16.5 ft/lb. My suggestion without a torque wrench is to use a 1/4 wratchet with a 1/2" socket the reason is you will not have a lot of leverage and thus less likely to strip. The pattern as mention previously is in the manual.
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Success with stage 1. I put in the new points and condenser, etc., got it all back together (with one delay when I lost a screw, and had to go to the snowblower shop to get a replacement), and tested it. I have spark! And the kill-switch circuits seem okay, except that I get spark whether it's in neutral or not--so I'll have to check that out later.
The carb is next. But I squirted a bit of gas in the spark plug hole and it caught for a round or two. (I didn't want to push it, because I'd removed the head and cleaned the piston area, and replaced with new head gasket. But I want to see if I can pick up a torque wrench on sale at Sears before I really try to run it. I used the suggestion of a small ratchet, so not much leverage.)
Thanks, all!
P.S. Then I went to mow my lawn, and my other recent rescue--the lawn mower--started pouring out oil smoke. (!!) Oil coming out the breather tube. I guess I'll search the forum for answers on that, or start a new thread.
The carb is next. But I squirted a bit of gas in the spark plug hole and it caught for a round or two. (I didn't want to push it, because I'd removed the head and cleaned the piston area, and replaced with new head gasket. But I want to see if I can pick up a torque wrench on sale at Sears before I really try to run it. I used the suggestion of a small ratchet, so not much leverage.)
Thanks, all!
P.S. Then I went to mow my lawn, and my other recent rescue--the lawn mower--started pouring out oil smoke. (!!) Oil coming out the breather tube. I guess I'll search the forum for answers on that, or start a new thread.
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Carb question
I did a carb rebuild and put it back together--and it runs! At least on full speed. When I pull back to idle, it dies. I haven't had time to fiddle with adjustments yet.
Question: Can someone tell me the correct hole to put the small throttle linkage wire in? I'm talking about the flat throttle lever on top of the carb body, which rotates as the throttle is opened and closed. It has three holes, one larger than the others. Unfortunately, I didn't note which of the three holes in the piece the wire goes into (the other end goes to the governor lever). Right now I have it in one of the small holes which looked very slightly less tarnished than the other two. Can't find anything in the manual to tell me.
I'm wondering if having it in the wrong hole could be part of why the engine dies when I throttle back. It seems as if you have to dismount the carb in order to remove and replace that wire, which makes experimentation difficult. Is it better to just bend the wire to get it out, and straighten it again when it's back in place?
(Another possible cause is that I slightly damaged the carb body removing the welch plug next to the idle mixture screw.)
Again, it's a Tecumseh Model No. Hs50-67074b (5 H.p. Snowthrower Model No. 38040)
Question: Can someone tell me the correct hole to put the small throttle linkage wire in? I'm talking about the flat throttle lever on top of the carb body, which rotates as the throttle is opened and closed. It has three holes, one larger than the others. Unfortunately, I didn't note which of the three holes in the piece the wire goes into (the other end goes to the governor lever). Right now I have it in one of the small holes which looked very slightly less tarnished than the other two. Can't find anything in the manual to tell me.
I'm wondering if having it in the wrong hole could be part of why the engine dies when I throttle back. It seems as if you have to dismount the carb in order to remove and replace that wire, which makes experimentation difficult. Is it better to just bend the wire to get it out, and straighten it again when it's back in place?
(Another possible cause is that I slightly damaged the carb body removing the welch plug next to the idle mixture screw.)
Again, it's a Tecumseh Model No. Hs50-67074b (5 H.p. Snowthrower Model No. 38040)
#24
Here is a link to a manual that should help. http://www.cpdonline.com/692509.pdf
I am not sure of the mounting on a snowthrower so my description may be off, but if it is typical of most, it should go in the forward most hole I believe. That would be the hole closest to the intake I think regardless of where the shaft is rotated...
I think the manual has some good illustrations so check there to be sure.
I am not sure of the mounting on a snowthrower so my description may be off, but if it is typical of most, it should go in the forward most hole I believe. That would be the hole closest to the intake I think regardless of where the shaft is rotated...
I think the manual has some good illustrations so check there to be sure.
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Here is a link to a manual that should help. http://www.cpdonline.com/692509.pdf
I am not sure of the mounting on a snowthrower so my description may be off, but if it is typical of most, it should go in the forward most hole I believe. That would be the hole closest to the intake I think regardless of where the shaft is rotated...
I think the manual has some good illustrations so check there to be sure.
I am not sure of the mounting on a snowthrower so my description may be off, but if it is typical of most, it should go in the forward most hole I believe. That would be the hole closest to the intake I think regardless of where the shaft is rotated...
I think the manual has some good illustrations so check there to be sure.
When you say forwardmost, do you mean toward the business end of the machine? That would be the larger hole. Closer to the [air] intake would be to the left as you're driving the machine.
Is there a trick to getting the wire on and off that doesn't require removing the whole carb (or severely bending the wire)?
#26
No good trick I know of, simplest to remove the few bolts and do it right. sorry again
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It runs pretty smoothly at full throttle, starts to surge and hunt some as I pull the throttle back about halfway, and dies when I pull it all the way back.
Suggestions?
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It runs pretty smoothly at full throttle, starts to surge and hunt some as I pull the throttle back about halfway, and dies when I pull it all the way back.
Suggestions?
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here is how the link should be connected. Also if you look at the rod, one end is a perfect 90 degree bend and the other is a bit more open. open end goes to carb.
One thing you need to check on this particular carb is if the metering pin/rod is free. Unfortunately you will need to remove carb again, remove bowl and float and shake carb. You should here what sounds like a BB rattling inside. This is the metering pin/rod. They are tough to get free, we can deal with that if you find it stuck (do not hear BB rattling). If you go to the manual, page 10, bottom diagram and look towards the bottom left you will see where it is in the carb. It looks like the float pin (about 1/2 long) and it meters the fuel in the idle circuit. When it stick you will get no idle
One thing you need to check on this particular carb is if the metering pin/rod is free. Unfortunately you will need to remove carb again, remove bowl and float and shake carb. You should here what sounds like a BB rattling inside. This is the metering pin/rod. They are tough to get free, we can deal with that if you find it stuck (do not hear BB rattling). If you go to the manual, page 10, bottom diagram and look towards the bottom left you will see where it is in the carb. It looks like the float pin (about 1/2 long) and it meters the fuel in the idle circuit. When it stick you will get no idle
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here is how the link should be connected. Also if you look at the rod, one end is a perfect 90 degree bend and the other is a bit more open. open end goes to carb.
One thing you need to check on this particular carb is if the metering pin/rod is free. Unfortunately you will need to remove carb again, remove bowl and float and shake carb. You should here what sounds like a BB rattling inside. This is the metering pin/rod. They are tough to get free, we can deal with that if you find it stuck (do not hear BB rattling). If you go to the manual, page 10, bottom diagram and look towards the bottom left you will see where it is in the carb. It looks like the float pin (about 1/2 long) and it meters the fuel in the idle circuit. When it stick you will get no idle
One thing you need to check on this particular carb is if the metering pin/rod is free. Unfortunately you will need to remove carb again, remove bowl and float and shake carb. You should here what sounds like a BB rattling inside. This is the metering pin/rod. They are tough to get free, we can deal with that if you find it stuck (do not hear BB rattling). If you go to the manual, page 10, bottom diagram and look towards the bottom left you will see where it is in the carb. It looks like the float pin (about 1/2 long) and it meters the fuel in the idle circuit. When it stick you will get no idle
I'll have to take the carb off anyway to change that. But I actually did shake the carb before installing it (having read about the rattle in the manual), and it rattled just as you said it should. I'll double-check, though, in case it's somehow gotten stuck since I put it on and ran it.
What I'm most worried about is that I might have screwed up the idle circuit when I took the smaller Welch cap off. The manual called for piercing the cap with a small chisel. Not having a small chisel, I tried to carefully drill a hole in the cap. I seem to have hollowed out the little chamber under the cap a little bit--though the holes for fuel to pass through were clear. (Stupid design, stupid me.)
BTW, any hints on where to buy a cheap tachometer for one-cylinder engines like this?
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If you had the rattle, I would doubt it is stuck now. probably did no damage with drill, I drill all of mine. Try partstree.com and type in 670156 as a part number. Very inexpensive but accurate tach.
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I moved the wire to the position in your photo. It runs better now. I can pull the throttle about 3/4 back instead of 1/3, but then it still dies. Fiddling with idle mixture and speed didn't solve that. One thing I noticed was, a part of the linkage comes into contact with the grounding clip as I pull the throttle to the Slow setting. It makes a little spark and starts to kill the engine unless I push it forward again. It does this whether or not I'm holding the kill-lever. Is this normal? The manual seems to say you can idle all the way back, and that's what the control markings indicate. But quite aside from carb-type dying sounds, this seems to cut the ignition. This is my first snowblower, so am unsure what to expect.
Also, do you happen to know what pressure should be in the tires? They're not marked, and the owner's manual doesn't say.
Thanks.
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Oh--when I took the carb off today, I realized that I had routed the spark plug wire incorrectly out of the flywheel area and brought it too close to the muffler! Singed it a little, but fortunately no worse. Is that supposed to come up under the flywheel cover through a little gap in the cooling fins? (If so, I need to take the head bolts out again; drat. Well, glad I bought a torque wrench.)
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I am assuming you have a sheathed throttle cable. with the engine off bring the throttle to slow to where it grounds out. Now loosen the clip that holds the sheathing and slide the cable so it disengages the clip. and tighten. You can also adjust this with engine running as well. Tire pressure at 20# should be fine and yes you will have to remove head bolts to remove cover to re route plug wire. It does run between some fins. once you get tach the adjustment screw is on the control plate, it will move the lever that the gov spring hooks on to. Sounds like you are almost there
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I am assuming you have a sheathed throttle cable. with the engine off bring the throttle to slow to where it grounds out. Now loosen the clip that holds the sheathing and slide the cable so it disengages the clip. and tighten. You can also adjust this with engine running as well. Tire pressure at 20# should be fine and yes you will have to remove head bolts to remove cover to re route plug wire. It does run between some fins. once you get tach the adjustment screw is on the control plate, it will move the lever that the gov spring hooks on to. Sounds like you are almost there
I'm confused on the grounding issue. I couldn't find a diagram or photo of the parts, so I'll try to take one later if necessary. But there's a rotating part of the throttle linkage, a little toward the handle from the carb. It has a tab sticking out, which moves toward a thin wire with a loop on the end that sticks out from the kill-switch circuit. (I believe that loop is kept from grounding by an insulator between it and the nearest metal.) The tab seems designed to slide between the loop and the insulator, lifting the loop slightly. And, I guess, grounding it. So it looks as though it's doing what it was designed to do--except that it kills the engine at low throttle. So I'm not clear what I should be seeing.
On the spark wire, this picture from the Toro site makes it look as though the wire passes under the carb and comes up on the auger side of the block. But I don't think my spark plug wire is that long. My unfortunately vague recollection is that it came out from under the flywheel cover, right behind where the plug is in this diagram. Make sense?
I'll figure out what you mean about the tach after I have it.
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Yes the when the tab on the control touches the wire loop it grounds the coil and engine stops. While tab is touching wire loop, loosen the clip that holds the throttle cable and slide the entire cable up so it breaks ground, then tighten clip. Or with clip loose move throttle control lever to "stop" position and tighten clip. Now as soon as you move throttle from stop to "slow" it should be breaking the ground. I am assuming you have a remote throttle and are not moving the lever on the control by hand, yes? Just route the spark plug wire any way it is away from muffler. If it is short come out of engine shroud on the top and the is a channel n the cylinder hed it will rest in so it does not get pinched
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Yes the when the tab on the control touches the wire loop it grounds the coil and engine stops. While tab is touching wire loop, loosen the clip that holds the throttle cable and slide the entire cable up so it breaks ground, then tighten clip. Or with clip loose move throttle control lever to "stop" position and tighten clip. Now as soon as you move throttle from stop to "slow" it should be breaking the ground. I am assuming you have a remote throttle and are not moving the lever on the control by hand, yes?
| FAST
|
| ON
| SLOW
|
There's nothing at the bottom to indicate STOP, but from what you're saying it sounds as if pulling the lever all way back is supposed to stop the engine.
If that's correct, then I understand everything except why it doesn't say STOP at the bottom.
(Actually the ON is on the opposite side of the lever. It might be for the ignition switch.)
I might get to work on it today, but otherwise, I'm going to be away from the project for a few days. I'll get back with my results. I've ordered the tach.
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What's correct RPM?
The little tachometer arrived today. Oddest thing I've ever seen, with a little vibrating wire. I was expecting something that hooked to the sparkplug wire. Anyway...
I can't seem to find the correct RPM in the manual. I did see a reference to idle speed of around 1750 in the smaller owner's manual, but couldn't find a full-speed setting.
It's currently running at about 3500 at full speed, and I can't get it to idle below about 2200.
I can't seem to find the correct RPM in the manual. I did see a reference to idle speed of around 1750 in the smaller owner's manual, but couldn't find a full-speed setting.
It's currently running at about 3500 at full speed, and I can't get it to idle below about 2200.