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Low compression on K301

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Joined
Feb 22, 2022
Messages
37
Location
Northumberland, Pennsylvania
Hi everyone, been awhile since I posted, for which I apologize. Life took over!

I got the 128 running great- I love that tractor. Just need to find a creeper gear for it.

However, I've been having more and more trouble with the 129. In addition to it not charging, the hydro started leaking, and the engine was getting harder and harder to start. Now it won't start at all. It puffed a good fireball out of the carb the last time it did start, a few weeks ago. It was dark, so that was pretty cool in a twisted kind of way.

Anyways, the engine has great spark and will not even cough on starting fluid. The compression tester said around 15 PSI. From reaching around, I know these engines have a compression unloader to help with starting, but 15 PSI seems too low to do anything.

I took the head off, and the cylinder wall looks immaculate. I THINK the valves are seating, but it's hard to tell. I'm trying to track down a leak-down tester. I also have a new head gasket, and after torquing it down to speck, no change in PSI. Is cylinder head warpage a possibility in these engines? Any other common issues with the K series that would cause low compression issues?

This thing is literally falling apart and I'm trying to decide whether it's worth it or not to repair it.

Thanks for your time!
 
Tom, so many things..valve adjustment,points adj.(backfire),broken ring,.I would start by proving valves are working and correct...With the head off ,roll it by hand with a super thin piece of paper under valve head,,if you can't pull it it should be close...a bad ring is hard to prove..
 
The automatic compression release will prevent you from testing compression. The Kohler service manual shows how to do a crankcase pressure or vacuum test with a home made "U - tube MANOMETER." BUT that requires you to get the engine started. & running. Yes, head could be not flat and not sealing. You could try some starting fluid, a shot straight into the carb while cranking should get you a pop or two.
 
The time to do a leak down test would be BEFORE the head came off and checking head for flatness would be BEFORE it went on with a new head gasket. We've all done stuff like that but slow down and think it thru and look at everything simple and that can be done before tearing things all apart. Good luck.
 
A backfire when trying to start can mean timing is off. Worn points can cause the timing to be off. How are you testing for good spark? A black carboned up spark plug can short out under compression even with "good" spark.
 
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