kohler kt725-3055 wont start

vkopecky

vkopecky

Forum Newbie
i bought this club cadet mower with this engine not running, things i have done verified cam and crank marks line up, verified good pistons, rings, and cilinders , set valves according to specs several times, push rods lifters and rocker arms all look good, no compression on tester, i am told this is normal with the compresion relief even though this model leaves the valve open longer instead of the crv asembly on the crank however it does pass a leak down test with flying colors. both cilyinders have spark . engine wont even try to start unless i loosen the intake valves a lot. thats just for diagnostics noy running it wiyh loose valves. carb is getting fuel. engine blows fuel back out of carb instead of sucking it in. if i put fuel directly in the spark plug holes it momentarilly trys to start but wont and usually backfires. magnet fell of flywheel i fixed that , carb shut off valve is working. any thoughts. ps engine has 100 hrs on it
 
You should have some compression even with the ACR working Normally that is between 65 and 95 PSI.

So something is not right.

When you did the leak down did you do standard test or the modified test? The modified test allow you to test the full piston area which if a cylinder is tapered or oval it is usually near the bottom of the stroke. YOu also would need leak down tester that operates at much pressure much less the standard 100 psi.
 
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StarTech said:
You should have some compression even with the ACR working Normally that is between 65 and 95 PSI.

So something is not right.

When you did the leak down did you do standard test or the modified test? The modified test allow you to test the full piston area which if a cylinder is tapered or oval it is usually near the bottom of the stroke. YOu also would need leak down tester that operates at much pressure much less the standard 100 psi.
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i will do the leak down again. I thought it weird that the intake valve is just finishing closing at the top of the compression stroke , i feel like it leaves no time for compression buildup, but as i stated both dots line up on crank/cam shafts
 
vkopecky said:
i will do the leak down again. I thought it weird that the intake valve is just finishing closing at the top of the compression stroke , i feel like it leaves no time for compression buildup, but as i stated both dots line up on crank/cam shafts
Click to expand...
As you say, that doesn't sound like the valve timing is right.
 
well i figured it out, i am guessing the camshaft gear is pressed on the shaft. i said screw it and tore it down again incase i messed up knowing i diddnt. dots lined up , looking at the cam lobes once again noticing that at top dead center the intake has just closed on compression stroke, well no matter what the dots say that cant work . so i acted like there were no dots , put it to top dead center and put the cam were i thought is should go. intake closing at the bottom of compression stroke . well this puts the dots off by 15 teeth , put it all back together installed on mower and fired right up and runs like a dream. never have i run across this issue in 30yrs . whats yall thoughts ? possible for that gear to spin on the camshaft or is it one piece or pressed on >
 
Glad you got it figured out, never seen this before though, guessing you tore it down thinking the dots were aligned if so how on earth did it run before , maybe there's other alignment marks you didn't notice , are they 180 deg apart ? Weird stuff
 
yes - some camshafts today have pressed on gears and they can spin and throw timing off. The carb spitting back out is a classic symptom of a camshaft that is out of time. Or sometimes a plugged exhaust.
 
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