x Mark misfires

txmowman

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Also, if your compression gauge is accurate, 150 compression is high. What did you adjust the valve gap to? How did you adjust? You wrote "it fires at high speed but misses at low speed", what does this mean? A coil has no determination of high/low speed. Do you have spark the whole time, but the engine has a miss?
 

tim4

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What type of spark tester? If you use a gap type tester, the standard for small engines is 1/4". If the coil will jump the gap, the coil is fine. Also, connect the clamp of the tester to the rocker cover bolt, not the spark plug itself. There is a diode in the coil. Unless you remove the ground wire from a coil, you might replace the wrong coil. Meaning, a failed diode in the #1 coil will make the #2 coil not fire. But, #1 is the failed coil.The bad coil was on the right side. I took the carburetor apart again and dirt got in the needle and seat so I cleaned it. It does not leak now but still acts like it is starving for fuel so the owner brought it to another shop for diagnosis.
 

hlw49

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First of all I had a friend help me clean the carburetotr and he cleaned the jets and checked the float. We checked the spark of the old coil by cranking the engine over and the spark he said was weak. I set the air gap of the new coil and we pulled the wire off the spark plug at idle and no difference. gI was referring to the housing that screws to the carburetor which is located behind the choke..
Still have not posted the model and spec no. what type of carb it is single or two barrel. If you have no air leaks and it is a two barrel carb one side of the carb can be stopped up as each barrel feeds its side on the engine. If it is a two barrel one of the welch plugs over the idle clusters can be missing.
 

tim4

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Still have not posted the model and spec no. what type of carb it is single or two barrel. If you have no air leaks and it is a two barrel carb one side of the carb can be stopped up as each barrel feeds its side on the engine. If it is a two barrel one of the welch plugs over the idle clusters can be missing.
Still have not posted the model and spec no. what type of carb it is single or two barrel. If you have no air leaks and it is a two barrel carb one side of the carb can be stopped up as each barrel feeds its side on the engine. If it is a two barrel one of the welch plugs over the idle clusters can be missing.
I have to get someone to read the numbers on the engine, I dcan't see it. It is a 2 barrell carburetor.
 
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