Tecumseh engine backfires

alanb21

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I was given a TroyBilt Tuffy rear tine tiller, that, after fresh gas, started right up. Kind of runs ok but it backfires out the muffler. The tiller model number is 12060 while the S/N is 120600250536. The engine is H30 35387V Any help will be greatly appreciated.
Thanks in advance,
Alan
 

Rivets

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With an engine that old I’m betting that you have an exhaust valve which is not closing fully. Cause would be carbon buildup around the valve face or sticking valve stem. The only way to find out is to remove the head and check.
 

alanb21

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To RIVETS and HLW49. Thanks for your replies. I'll take a look at the engine after I finish replacing the axle and tine seals. They should arrive by Wednesday.
Can you tell me how old this engine is?
Alan
 

Rivets

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Not without all the engine numbers. Tecumseh stopped building engines in 2008, so at least 15 years old.
 

alanb21

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This is what I have. The tag reads H30 35387V with a DOM 5051 0. I tried uploading a photo of the engine tag but the file size is too large.
 

tadawson

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Carbon, maybe . . . but seems more likely that if it is that old and has not been maintained that it needs a valve adjustment.
 

alanb21

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I agree to all the suggestions given, in that it has to do with the valve adjustment. Since it was given to me and I don't know the history or how many owners it has had, I will hazard to say the maintenance is possibly an oil change or two during its life but that is only a guess.
Alan
 

Rivets

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Even if the valve clearance is off you still have to remove the head to get the valves out. That is a good time to check and clean the valve seats and faces. L-head engines are a little more difficult to do the job, but both the cleanliness and clearance needs to be done. Valve clearances are intake .004” and exhaust. .008”.
 
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