Tiger Cat running on one cylinder

fortay

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Hello everyone. I'm new to this forum and I'm sorry to say that I come bearing no gifts, just needs.

In the middle of mowing my Tiger Cat(STC52V-691FX) started running rough, almost sputtering. It didn't matter if I had the blades on or off. If I pushed both control arms forward at once, the rpm would die down. I figured out that one side wasn't getting spark, so I replaced both ignition coils, air filter, and spark plugs. Then I realized it was running only on the number 2 cylinder.

After putting the thing back together, the engine won't start if I tighten the bolts holding the engine cover. If I loosen them, the engine will start, but will continue to run rough as before. I just checked, and once again, one side is not getting spark.

I removed the number 1 valve cover and regapped the valves. I sanded the coil posts. The mower starts and immediately dies if I pull the kill wire off the coil.

Does anyone have any ideas?
 
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StarTech

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Model number correction STC52V-691FX No serial given. The problem is with the Kawasaki FX691 spec number number for troubleshooting. But currently it sounds like #2 cylinder is down provide the OP is pulling #1 coil wire.
 

StarTech

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Which plug wire you are pulling that is killing the engine?
 

StarTech

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Then a leak down test on #1 is in order. You may have a blown gasket, bad piston, or broken valve / valve seat. Leak down should point you in the right direction.
 

Romore

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I would remove that valve cover and have a look. I wonder if a rocker stud has backed out.
 

cpurvis

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How likely is that with only 371 hours?
That will depend on how hot the engine has gotten. Have you kept the cylinder fins clean?

If the engine overheats, the valve guides tend to loosen and work their way out of the head. Eventually they move so far that the rocker arm hits them resulting in a bent or broken push rod and the valve just stays on its seat. Thus the dead cylinder.
 

bertsmobile1

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If it won't start with the engine cover bolted down tight start by looking at the kill wires on the coil
Good chance you will find a spot where they are being pinched onto the block and are shorting out.
The kill is a ground wire so if it is bare anywhere and the bare bit touches any metal then no spark.
 
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