Engine won't rev up & dies


  #1  
Old 04-05-04, 03:33 PM
Tools
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Tecumseh wont rev up,dies

5 HP horozontal shaft on garden tiller,come with the house when i bought it,former owner had the carb off so I put it all together, it will only run at an idle after a lot of pulling on the rope to get it going.New plug,good spark,good compression,check the valve clearance,valves dont seem to be sticking,took carb back of,soaked in carb cleaner,put new inlet nedle valve and seat,float is good fire it up only runs on idle,adjusted air screw on side,adjusted screw on bottom of bowl,all evey which away.the instant i open the throttle a hair it dies.Im starting to think the reasonit dont run is becouse its a Tecumseh,any ideas.
 
  #2  
Old 04-05-04, 04:04 PM
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Hello: Tools

Remove the carb bowl. Look closely at the shaft on the screw. Close to the nut end will be holes in the recessed area around the shaft near the nut end. Clear those holes out.

While the bowl is off, two holes in the center shaft of the carb will be notice. Clear those out. Up the center of that shaft will be a fuel jet hole which goes completely up the center of the carb into the center of the venturi. Clear it out.

Those areas allow fuel to flow at off (above) idle speeds. If they are clogged or restricted, engine will not acceleration but will die. Also check the tiny holes in the side wall of the venturi barrel of the carbs main air flow body.

Based on the problem description, the carb is not likely allowing gas to pass through the jets. Fuel starvation occurs and the engine dies.

Most likely I haven't covered all of the possibilities. The other resident small engine service and repair professionals in the forum may be able to offer additional suggestions, advice & help.

Check back on your question several times over the next few days for additional replies.

Buy a small engine repair parts, generic repair manual. Additional help are all available at all local small engine repair shops and or lawn mower repair shops in your area. Shops and dealers are listed in the phone book directory.

If you need further assistance, use the reply button. Using the reply button moves the topic back up to the top of the daily topic list automatically & keeps all communications in this one thread.

Regards & Good Luck. Sharp Advice.
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  #3  
Old 04-05-04, 05:46 PM
T
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It could be the diaphram is cracked or has a hole in it. Not sure if this engine has one but I had an old VW that acted just like this. Replaced the diaphram and it pulled like no other.
 
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Old 04-08-04, 03:15 PM
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Success?

How did you make out? You didn't mention if you have fresh fuel - complete fuel system flush. Could be as simple as that. Fuel older than 90 days loses its volatility causing the exact symptoms you are experiencing. Let us know!
 
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Old 04-08-04, 03:54 PM
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Puey61 is correct. Allways use fresh fuel. Fuel can occasionaly go bad in 30 days time. If you keep fuel for 30 days or longer, use Stabil in your gas can. What this stuff is, is a fuel stabiliser. It has certain ingrediants to keep the fuel fresh. I use it and many others use it. Please check back and let us know how it went...
 
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Old 04-08-04, 06:05 PM
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Gas is brand new,carb cleaned 3 times in carb cleaner(soaked),valves are not sticking,tappet clearence is 10.new spark plug,head gasket dont leak, new points and condenser, good compression, will only idle,will not rev up even 50 rpm, if open throttle a hair engine dies,i think its the carb but new one is 120.00 bucks,engine is too old to warrent that much.
 
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Old 04-08-04, 06:13 PM
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One other piece of the puzzle,on the bottom of the bowl theres a fitting that a jet screws into and it holds the bowl on,there is 3 paper thin gaskets on there and the one thing i did notice is that if i double the amount of gaskets the motor readaly starts but still wont rev up.If I put still more gaskets or washers it wont run at all,Tecumseh- pure junk.
 
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Old 04-09-04, 12:16 AM
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I agree with you...it sounds like you still have a carb problem. Call around the small engine shops in your area. I bet you can find a good used carb for less than that. Check ebay too.

Try this if you want to give it another shot...Go to a welding supply store and buy a set of tip cleaners. They are around 3 to 5 dollars for a set. Take the carb back off. Soak it in chemdip or similar automotive carburetor cleaner for a couple of hours. You'll need to replace the inlet seat after this. Use compressed air and a rubber tipped blower to blow out all the passages. Use the tip cleaner to run through all passages. Take the welsh plug out of the side of the carb. You'll probably have to drill a small hole in it and screw a screw partially into it to pull it out. Behind that plug you'll see some small passages. They may be restricted, and now you have access to them to clean them out. Also , look at the bowl screw. There are small holes in it. Depending on the year of the carb, there may be up to 3 in the sides of that screw. Down near the base of the screw, there should be two holes that oppose each other. Make sure they are clear. Then, near the end of the threaded end of the screw, there should be a very tiny hole in an un-threaded section. It is very small, and can be almost invisible if it is clogged. Make sure it is clear. This is a common spot for restrictions and will keep the engine from running. Install a new welsh plug, reassemble the carb, make sure the float is set correctly, and try it again.
 
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Old 04-09-04, 05:27 AM
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on the bottom of the bowl theres a fitting that a jet screws into and it holds the bowl on,there is 3 paper thin gaskets on there and the one thing i did notice is that if i double the amount of gaskets the motor readaly starts but still wont rev up.If I put still more gaskets or washers it wont run at all
Intertesting point you made above. Changing the position and relationship of the screw changes how the engine runs. Which indicates the two parts, when put together with tiny changes alters how the engine runs.

Possible deduction may be the existing parts are not the original, which would include the gaskets. OEM would not have multiple gaskets. Either the original gasket is not installed or the parts other than the gaskets are not OEM.

In any of those cases or instances, having the service manual with part pictures and the assembly of how they all go together plus having the correct parts would allow the assembly to be correct and the engine run as intended. Well as new.

Summations:
1)
Yes. I agree. It is a carb problem based on your above additionally provided information Tools.
2)
Logical deduction indicates that carb needs the correct parts, assembled correctly and installed correctly and the problem would than be resolved.
3)
Take carb to local small engine or lawnmower repair shop. Purchase correct carb parts, assemble, reinstall and be done with it. Engine will again run as it should, regardless of brand.
4)
Tecumseh is a good engine. Will run and operate well. When any engine, regardless of brand, is not assembled correctly, does not have the OEM parts or has been "Fixed" incorrectly, etc, brand name makes no difference.

Sharp Advice.
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Old 04-09-04, 05:48 AM
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I'll second that, cheese. Tool should find a good used carburetor. Tool, if you follow cheeses advice and try your hand at carb. service again, be very very careful when removing the welch plug on the left side of the carb. If you pierce this plug too deep, you will poke through the wall of the carburetor. You will then have no other choice but to find another carburetor. Do you have the engine ID #'s handy, I'll be glad to look up the carb. and price for such. The price you were quoted seem high to me, although it may not be. I'm not familiar with the solution that cheese suggested you soak the carburetor in but I do know that the solution we use here works fantastic. NAPA product# 6401. This is a very strong solution. Use caution when handling - wear protective gloves and let the carburetor soak for only 20 minutes. You will not need to remove the welch plugs using this solution, just use compressed air when finished soaking. If your carb. has a plastic fuel inlet, letting the carb. soak more than 20 minutes will loosen this fitting up and you will then need to replace it. Good luck at let us know your model and serial numbers.
 
 

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