8hp Tecumseh carb ?

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  #1  
Old 10-04-03, 10:46 AM
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Question 8hp Tecumseh carb ?

I need help. I read the owners manual and closed both the high and low spped idel screws all the way in and the opened them 1 1/4 turns. I can't get the snowblower to idle smoothly at all. In high idle it backfires and shoots a miny flame through the exhaust. In low ideal it revs and drops revs and drops like it is going to stall out. I sprayed the carb down with cleaner as it is 14 yrs old and my father-in-law did nothing to it. Do I need to rebuild the carb and if so how hard will that be.

Thanks for all your help always.

Regards,

Doug
 
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  #2  
Old 10-04-03, 10:59 AM
Joe_F
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Sometimes the muffler will cause that with bad pieces getting shot through it.

Yup, sounds like a wasted carburetor. The kit is cheap and rebuilding is fairly easy. Any small engine shop will have the needed parts. Throw out the float too, they often leak.
 
  #3  
Old 10-04-03, 12:16 PM
Tcumcman
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8HP Carb Problems

Money Pitt,

Very often, snowblowers, due to their infrequent use, will have
carb problems. Though you may have drained the fuel from the
carb bowl and tank before storing the machine, fuel residue in
the carb circuitry will form a varnish in there. I'd try cleaning it
first with some spray, install a kit (available from your local
Dealer for less than $10), and try that. Proper cleaning of the
carb is very important, and you may want to take it to someone
familiar with doing that. Usually, most shops will rebuild it for
$30-40 or so. The idle circuit is tough to clean sometimes, and
following a good cleaning/rebuilding, it still does this....it's time
to buy a new carb for around $70-80 on the average.

Tcumcman
 
  #4  
Old 10-07-03, 09:39 AM
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Rebuild Directions?

Well i picked up the rebuild kit. It is in a bubble pack with no directions. The owners manual shows all the parts and roughly where they go with pointers but does anyone have an actual How to process direction pamplet? I know I will be getting help from my 14 yr old daughter and would like some directions in case the disassembled parts get moved around.

Thanks,

Doug
 
  #5  
Old 10-07-03, 09:58 AM
Joe_F
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Check on the 'net for "Tecumseh Carburetor rebuild" on www.google.com.

I have seen instructions floating around on the rebuild of these.

Fortunately, I have a Tecumseh shop manual, big bulky ass thing!
 
  #6  
Old 10-08-03, 12:16 AM
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Hello Doug!

This is a very simple carb, and is not hard to build. Just pay attention to which parts came from where, and how they were attatched. There are diagrams online, as mentioned. Let us know if you get into trouble...we'll be here to help.
 
  #7  
Old 10-10-03, 06:47 AM
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Thanks for all the responses. I found a web site with simple directions and a parts chart. That was my biggest need since my daughter wants to help. This way I will know where everything goes back and in what order if the peices are moved around.

Cheese - It does look very simple and since it is supposed to rain this Sunday, it looks like it will be the weekend project.

I have another question. I found an old fog light on a garage shelf. Just for fun, how can I hook it up to this 8hp motor? I have to make my tools look like TOYS so my kids will want to use them.

I put a chrome skull shift on the gear box and put flame model decals on the Auger body {ah ah ah} Oh sorry Tim the Tool Man Taylor just crept out. Last part of the story is my father-in-law got bored waiting for me to tune this up for him so he bought a new 9hp craftsman snow thrower with a 29" auger. His shed door was only 28" wide until I got the saws-all out {ah ah ah more power}

Thanks for all the advise.

Doug
 
  #8  
Old 10-10-03, 07:50 AM
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Lol. Tell your father in law to pass some things my way. LOL. Gee whiz!



I did score an Echo PB400E blower from my neighbor who was throwing it out , along with a 110V air spray gun (new!). Amazing what people throw out.

Watch Mike Merritt and I breathe life into this one (hopefully ).
 
  #9  
Old 10-10-03, 11:09 PM
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Does the machine start with a battery? Is there a red wire coming out from behind the engine shroud? If no, then it will not power the light.
 
  #10  
Old 10-11-03, 06:19 AM
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Thanks Cheese. This is the one that you guys helped me find an electric start for on e-bay. And no there is no battery or red wire.

I guess I can't trick the blower with a fog light. Well back to decals and new paint.

Doug
 
  #11  
Old 10-12-03, 06:19 AM
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Unhappy I Think I Screwed Up

Well I took the carb off and couldn't get the accelorator "rods" off so I removed the metal peice that hooks to the engine block. I rebuilt the carb with no problem and reinstalled everything the way I thought it went. It was easy and in less than an hour. My problem now is I have no low idle. I move the throttle and it does nothing until I put it in off. That shuts it off by grounding it.

How do I fix the idle. I know I must have messed up the the "rods and or the metal attachment.

PLEASE HELP....so close yet so far.

Doug
 
  #12  
Old 10-12-03, 07:53 PM
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Oh boy, you went and did it this time!!! (JUST KIDDING!!)

The governor setting was lost when you took the "rod" off. To correct this, loosen the arm up again, just loose enough to move it. Turn the governor shaft coming out of the engine clockwise all the way, and move the arm away from the carb as far as it will rotate, and tighten it back up. Make sure it is all in the correct position before tightening it. Let us know how it goes!
 
  #13  
Old 10-13-03, 11:36 AM
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Cheese. Thanks, but one more questions, what should the throttle lever be set on to make the refered correction to the governor {off or full}?

Once I have mastered this then it is onto the $100.00 MX3 my 14 yr old daughter just bought.

Thanks,

Doug
 
  #14  
Old 10-13-03, 09:49 PM
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Set the throttle to full, and make sure the actual throttle shaft on the carb is all the way open.
 
  #15  
Old 10-18-03, 01:20 PM
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Hi Cheese, I think you are right... I really did do it. I set the throttle on high and opened the carb until it hit the stop and set the govenor shaft as you stated. Now I don't have a high idle. I also noticed on the throttle that the adjuster screw doesn't even come close to the springed tention to keep it on high idle.

Please help more if you can. I am now totally lost. The engine runs nice and smooth but only in one idle position.

Thanks,

Doug
 
  #16  
Old 10-18-03, 07:29 PM
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Something is still misadjusted with the gov. setting. Move the throttle wide open while watching the governor. Note which way it moves when you open the throttle. Then, loosen the governor screw. Then move the governor shaft coming out of the engine the same way...all the way, Also make sure the carb is wide open. While both of these things are held to the limit, tighten the governor adjustment again.
 
  #17  
Old 10-27-03, 09:55 AM
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Cheese, you were right something was still misadjusted. The choke/throttle control arm was set wrong. I had it positioned so the linkage rod went under the gas line and the control was in a horizontal position. Through trial and error I discovered that the control should have been pointing straight up and the linkage went above the gas line to the governor. Now my problem is with the choke/throttle. The set screw to increase/decrease the choke speed... When it is cold and in full choke/throttle the "wheel" seats againist the mentioned screw, but when I try to reduce the throttle the wheel does not follow the set screw {no tention}. It hangs there. {this is all up in the lever mechanism area} If I rev it several times it will finally drop and the idle comes down. I won't be able to do this when the cover is put back on. What is sticking this in place?

So close and so is the snow.

Thanks,

Doug

P.S. is does run smoothe as silk though
 
  #18  
Old 10-27-03, 09:21 PM
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I'm not sure I understand exactly what the problem is....the choke shouldn't be connected in any way to the governor. What are you referring to as the "wheel"? The screw you mentioned...is it on top of the carb exposed? Sounds like the idle speed screw. The end of that screw should contact the flat on the carb body at idle.
 
  #19  
Old 10-28-03, 05:33 AM
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Cheese, the screw I am talking about is the set screw on the throttle lever. It, from what I can tell, pushes against a wheel that maintains the pressure on the linkage to the govenor regulating the fast idle speeds. The wheel hangs and does not follow the set screw when the throttle lever is redused. This all pertains to the throttle/choke lever mechanism. This maybe part of the old problem prior to the carb rework as this snow blower is 14 yrs old and my father-in-law playd with it without knowledge and just gave up when he couldn't keep it running.

So close but so is the snow (we had flurries last week)

Thanks,

Doug

PS - I did notice that the linkage wire from the carb to the governor is bent several different ways {not natural, almost liked yanked on}. Could this be causing the throttle wheel from moving?
 

Last edited by Money Pitt; 10-28-03 at 07:09 AM.
  #20  
Old 10-28-03, 10:09 PM
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A bent linkage will cause all sorts of problems. Might be best to get a new linkage. Post your engine numbers so I can look up your engine info and diagrams and get a better idea of what linkage setup you have. Maybe you have some setup that is more specific to snowblower engines and I would be unfamiliar with that (no snowblowing down here in S. Georgia, lol).
 
  #21  
Old 10-29-03, 06:02 AM
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Thanks Cheese, Since I am at work and don't have the manual with me I grabbed the info off my other post regarding the electric start that I was looking to add to this unit. I got the starter off e-bay and the install was a breeze.

I am glad that there is a site like this. The information is as follows:

following is off the owner's manual:

Model # 536.886800
25 inch wide cut
Dual Stage
8 hp Snow Thrower

Craftsman engine # 143.786052.

Let me know if you need more info and I will get it tonight.

Thanks again, your help is greatly appreciated.

Doug

Mazda MX3 project still sits until this is fixed. My daughter is not happy
 
  #22  
Old 10-29-03, 11:50 PM
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Ok, the screw you are talking about...does it thread into the aluminum of the carb body? And does it contact a tab that is bent downward on the "wheel" you mentioned? If so, the wheel is the throttle shaft, and the screw is the idle speed screw. The throttle shaft with the tab that contacts the wheel probably won't contact the screw until it cranks up and the governor forces it into contact with the screw when the engine is set to idle. If it won't contact it when the engine is at idle, something is wrong with the governor settings or the linkage. (unless the throttle is sticking and won't trun far enough to contact the idle screw). To find out if this is the problem, try turning it by hand to see if it easily moves enough to touch the idle screw. If it moves easily, it is not stuck. If it doesn't, then it needs cleaning.

From what I can tell, the throttle cable goes to the governor lever, then the linkage to the carb goes from another hole in the governor lever to the throttle shaft. Does this carb have a manual choke that has a tab in the shape of an arrow that points in the direction to turn it to choke?
 
  #23  
Old 10-30-03, 05:41 AM
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Cheese wrong screw! What I am talking about is at the throttle lever. There is a screw that rest on a wheel. It holds it in high idle when the lever is in the highest position. when you lower the lever for slower idle towards the off position the wheel does not follow the setting screw. Then if you raise the lever back to high idle it does not increase the speed. If I rev the carb a couple of times then the wheel becomes unstuck and rest back on the screw reducing the throttle speed but then won't return to high speed when the throttle is raised. I think this is all linkage problems but I do not know how to fix or adjust. The linkage from the carb to the governor is twisted {bent} like someone yanked on it. Is it possible to get a new linkage wire or is it time to take it to someone? I really prefer not paying for labor.

Thanks for all your help,

Doug
 
  #24  
Old 10-30-03, 10:49 PM
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Now I get it...(I think my skull gets a little thicker every year, lol).

It still sounds like a linkage related problem. I would get new linkage to replace whatever is bent and go from there. Bent linkages will bind and cause all sorts of problems. (not to mention it is nearly impossible to set the governor with bent linkages). If you take it somewhere, they will replace it too, so why not do it yourself? Shouldn't be more than a few bucks.
 
  #25  
Old 10-31-03, 04:51 AM
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Thanks Chees, It is off to the small engine store for linkage replacement. I hope that gets this blower going. I have 300 ft of side walk and a double wide 20 fft by 65 ft long drive. I think Jersey is in for some snow this year.

This site is great. Again thanks for the help. I know you live in GA, but I have been there when it has snowed and everything shuts down including the Airport for 2 days !!!

Doug
 
  #26  
Old 11-01-03, 09:45 PM
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Yeah...it snows in Georgia, but not where I am. I am about 20 miles north of the Florida border. We see a bit of snow occasionally, but not enough to use a snowblower on. Schools shut down when we do get a little snow. I'm not sure if it's because people don't know how to drive in it, or so that the kids can go play in it, or a little of both. It only happens maybe once every 10 or 15 years.
 
  #27  
Old 12-10-03, 12:27 PM
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Its working

Cheese, I finally got the new linkage wire just before we got 12" of snow last Friday. Put it all together and I still could not get the SOB to throttle up. In frustration while it was running I pushed the governor. It then dawned on me that I should have been adjusting the throttle linkage with the blower running. I kicked through the 12" of snow like butter. I now think that I have it reving a bit to high. I plan to back it off after I recoupe from doing all the snow at 2 places. Yes my father in law bought a new blower, I got his old one but used both of them to clean 4 houses. I think I need to go back to school and brush up on my math because it just doesn't balance out. 1 blower - 1 house should equal zero work!!!

Thanks again for all the help. For under $120 dollars I got a 8hp self propelled snow blower and my back doesn't hurt!!!

Doug
 
  #28  
Old 12-10-03, 08:25 PM
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Glad you got it going!
 
  #29  
Old 01-05-05, 08:49 AM
rossliana
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Similar Tecumseh Carb problem

I have a 10hp tecumseh snowblower. already rebuilt the carb, adjusted and runs well-almost. The problem is the govenor lever dosen't return to idle when the engine is running. Carb linkage operates as it is suppossed (linkage returns to idle) to when motor is off but when motor is running linkage won't return to idle. You can push the governor lever back to idel but it will creep back up to full throttle in 10 to 30 seconds. Any ideas?
 
  #30  
Old 01-05-05, 11:49 AM
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I had the same problem last year when I got done with everything. It turned out to be that the spring was spung/stretched and would return to its most used position {full throttle}. A replaced linkage spring did the trick and was inexpensive. My thrower is 15 yrs old and is solidly stronger {frame wise} then comparable ones sold today. Good luck on your repairs.

Doug
 
  #31  
Old 01-09-05, 03:00 PM
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Yard Machine with Surging(Hunting) problem

I have an 8 hp Tecumseh engine on a Yardmand snowthrower. It's been running great when all of a sudden it haas developed this surging or hunting problem when not under load. I've clean out the carburator and checked the float and all looks good. It has a solid screw in the bottom of the bowl so it is one of the non-adjustable types. When I had the cover off I could see the governor arm moving back and forth causing the idle speed to go up and down. Under load it works great. I drained the fule and put in 89 octane and it helped a little. Should I try rebuilding the carb or just replace it?
 
  #32  
Old 01-10-05, 08:10 AM
Azis
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Hi gilcalif,
If your unit is fairly new, 10yrs old or newer, you may very well have no adjustments. There may be an idle speed adjustment however. You may be lucky and get it to smooth out by adjusting it. Try turning it in a bit and see if it will smooth out. If you can get it to smooth out but the idle is too high or it wont smooth out,and there are no other adjustments, a carb cleaning at the least is worth a shot. One problem with the newer carbs is the amount of plastic used in the construction. This plastic will not hold up to industrial strength carb cleaners. Also the main jet may not be romovable. The only parts that are replaceable are the float needle and seat and bowl gasket. Tecumseh recomends replacing the bowl gasket ne time the bowl is removed. You could try using some spray cleaner disasembling the carb and cleaning and replace the bowl gasket. There is no kit persay for these and I see no reason to mess with your needle n seat ifn it aint broke.
I also just remembered something on those carbs but forgot now where the tech reference is.... (lil help Cheese, Snoman,...ne one)
I think those carbs have an "emulsifier" ??? I think they called it, to test, with the carb removed, holding it close to your ear, roll it over and listen for a soft clunk.
U might have a look through this manual http://www.cpdonline.com/692509.pdf
as will I when I get time cuz now I gotta satisfy my own curiosity.
 
  #33  
Old 01-10-05, 08:14 PM
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Hello gilcalif!

Welcome to DIY.
If yours has a solid bowl screw, then it's not the plastic model that Azis is thinking of. You should be able to straighten out the surging by removing the bowl screw and cleaning it and the bowl. The screw should have 4 holes in it. 2 oppose each other near the head of the screw. One goes down the center. One is very tiny and is usually where the problem is. It is located in an unthreaded section of the screw near the end.
 
  #34  
Old 01-11-05, 09:10 AM
Azis
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The metering bolt is an often overlooked item when cleaning the carb and usually the problem.
gilcalif may not have a plastic constructed carb however if he were to by the base replacement, it would have the plastic I beleive. I started seeing them on smaller mowers less than 3 yrs old last summer. The base (as Tec calls it) replacement for most all tecumseh at least that I checked on, were of the plastic construction and the external parts were to be transfered for the particular application.
Hopefully I am wrong or they change cuz I hates them lil buggers ya cant do nothin with.
 
  #35  
Old 01-12-05, 12:19 AM
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I agree...they are aggravating. As far as I know, they don't have a metering bolt though, just a flip bail wire that clips the base to the underside of the carb, right? Or is there something I haven't seen yet?
 
  #36  
Old 01-12-05, 09:20 AM
Azis
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No the ones with the solid metering bolt and the steped bowl...? Trying to remember now but had a plastic inset for the float n needle to hang off. I can't remember now the main jet but I think it was not removable and may have been synthetic also. One in particular I remember was a 22" murray with 3.5hp Tec. Never could get it to run under a load and barely got it to idle smooth without hunting. It wasn't worth the 60 bucks for a new carb (wound up donating it to the High School power mech class ) although I did research it and found that there was basically one base carb made for most applications, only the external components were different.

I am planning on taking the Tecumseh Dealer class in the next month or 2, heh think I will start logging some ?'s
 
  #37  
Old 11-30-08, 12:22 PM
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Smile Cheese not sure you can help high rev engine!

Originally Posted by cheese View Post
Hello Doug!

This is a very simple carb, and is not hard to build. Just pay attention to which parts came from where, and how they were attatched. There are diagrams online, as mentioned. Let us know if you get into trouble...we'll be here to help.
I bought a brand new snowblower two years ago with the 8HP Tecumseh engine. For the first two years it ran rough it seemed to be hunting. It would rev up and down and I would have to play with the choke to keep it going (would stall out on idle). This year I decided I would find out what was wrong and on inspection I noticed the governor arm was moving back and forward. I tried to adjust the govenor and the engine rev'd quite high. I then went on line and adjusted it according to your posting.

Now the engine works at only one rev very high and can not be idled. It runs at this high rev even though the trottle arm on the carb is not fully open. It is just of the idle screw (half way to the back stop) and not near it's back stop. The engine no longer does the hunting thing and the choke can be left wide open at this high trottle.

It is as if the trottle arm is stuck full against the back stop. Yet as I mention she isn't near the back stop. Lowing the trottle control below this high rev and she dies.

It looks like my fiddling with the govenor some how cleared up the hunting problem but something else is wrong now.

What would you suggest? Should I just replace tha carb?
 
  #38  
Old 11-30-08, 08:38 PM
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Wow, this is an old thread (5years ago)

Sounds like an air leak or carb problem more than a governor problem. The engine should idle with the carb at the idle stop screw no matter how the governor is set. You don't want to run it revving high though...especially a tecumseh.
 
  #39  
Old 12-01-08, 11:39 AM
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Yuck! Sounds like a may have runined the engine!

Originally Posted by cheese View Post
Wow, this is an old thread (5years ago)

Sounds like an air leak or carb problem more than a governor problem. The engine should idle with the carb at the idle stop screw no matter how the governor is set. You don't want to run it revving high though...especially a tecumseh.
Cheese thanks for the response!

An air leak sounds like I blew a gasket. Would the gasket be on the carb or do you think I messed up the engine it self? Rev'ing high in Boston may have caused a serious problem!
 
  #40  
Old 12-01-08, 07:38 PM
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If the gasket between the carb and intake, and the gasket between the intake and block are good and not torn or leaking, then I'd say you have carburetor problems. I don't think you have serious problems.
 
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