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one piston is not combusting

Posted by rockjessemax none (My Page) on
Fri, Dec 2, 11 at 17:20

I have replaced both coils on a 22hp tecumseh plus two repair kits for both carbs. all wires look to be properly in place (connected) My trouble-shooting is as follows. I am getting fire to both spark plugs. switched sides with plugs and still the same side will not combust. so, i know the plugs are ok.
when the plug wire is removed from the (dead side) there is no change in the engine, removing the plug wire from the other side and of course the engine will stop. I know the (bad side) plug is firing because a strong spark is detected by sight and (ouch) feel. This engine is a duel everything. ENDURO VT, TVT 691 (600803A). I ask this prior to spending any more money in hopes that i am overlooking something simple.


Follow-Up Postings:

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RE: one piston is not combusting

Is this the V-twin that was only produced a few years? Check the compression on the dead cylinder. One of the valves may be stuck open due to old fuel gumming up the valve stem. If this is the case, perhaps the valve pushrod has fallen out of position. Removing the valve cover may be necessary.


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RE: one piston is not combusting

Yes, It has two black boxes on either side of the engine with DOV. I assume this is the valve cover? Looks kinda simple to remove. I'll take it off after I hear from you again.


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RE: one piston is not combusting

  • Posted by baymee LehighValleyPA (My Page) on
    Sat, Dec 3, 11 at 6:36

The valve cover boxes are usually square dome shapes with 4 bolts. Sometimes the valve seat itself comes out, requiring head removal and peening around the edge of the seat to keep it in place.

If the end of the valve stem doesn't come up equally on both sides, it's a good bet that the seat is out. A leakdown test is the way to check for bad valves in an engine with compression release features.


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RE: one piston is not combusting

thanks for the feed back. That sounds like a little more involved than my talent will stand. I have a local guy that I can trust. Again, THANKS


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RE: one piston is not combusting

Could be a broken valve spring too....if its broken you loose the compression in that cylinder deeming it worthless.

Easy fix with a valve spring compressor...


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