Duraforce that is extremely hard to start.

Elfiero

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I have an engine from a gold pro duraforce that is extremely hard to start. I have replaced the coil and the carburetor with those from a know good, running lawnmower and it still won't start! the engine has 120psi of compression, and the reed valve seems to function correctly. What am I missing? The only way I have gotten it to run at all is with starting fluid, even then it seems "lethargic"- HELP!
 

Russ2251

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Verify fuel flow to carburetor. Is the bowl filling?
 

Elfiero

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I did check that and YES- the bowel is in fact filling with fuel.
 

jp1961

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Hello,

OK, you've got spark (double check with the plug removed and shorted to the cylinder), good compression, and a known good carb.

I'd check the crankcase seals, if they are bad even with good compression, the engine won't be drawing air/fuel through the carb.

I bet the seals are bad or if the engine ever backfired they may be totally out from the crankcase.

Regards

Jeff
 

1saxman

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Don't use starting fluid! Put the 2-cycle mix in it. You'll use starting fluid and it'll wash all oil out of the cylinder, possibly freezing the rings if any humidity gets in there. I've been reading a lot of problems with the Dura-Force and I have to say these engines are getting very old in the lawn mower world. People are now experiencing things that were unheard-of when they were in production, like throttle plates breaking off and getting sucked into the engine, carbs flooding, crankshaft seals blowing out, etc. Actually, the carbs did flood years ago and the crankshaft seals also popped out of the Dur-Force sometimes. :) But the fact that so many are still in service is amazing. With proper care, maintenance and sensible use, a Dura-Force should not wear out.
 

javjacob

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NEVER use starting fluid on a 2 stroke! Crank seals are probably bad causing a lean condition. This can destroy a 2 stroke engine especially with starting fluid which washes the lube off the cylinder and the cranks and rod bearings.

The carbs flood because the needle and seat need replaced. This is a common issue because they didnt have a fuel shut off valve. Get a fuel shut off valve and get the Briggs pilot jet (part # 801308) The Briggs pilot jet is a must have for all Duraforces and fixes the lean running condition they all have from the factory. Also if you don't have the right throttle plate get part # 98-7047 which has a larger hole.

The Duraforces are great engines but need the right throttle plate #98-7047, Briggs pilot jet #801308 and a fuel shut off valve. People that don't do these 3 things will always have problems and think the Duraforce is "problematic" which it really isn't.
 
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