Kohler CH740 power issues.

[ILENGINE]

That is where I found those numbers myself, although I almost missed it. Thoughts on pulling the heads and inspecting?

I would start with a leakdown test to see where you are loosing compression.

 

[F150Fan80]

I would start with a leakdown test to see where you are loosing compression.

This would be my first time doing a leak down test. I read through the service manual and it seems very straight forward. Any tips for performing the test? Easiest way to determine a leak? Soapy water maybe?

 

[ILENGINE]

You use your ears. If the air from the cylinder is coming out of the air filter housing then you have a leaking intake valve, not to be confused with air that could be coming out of the breather tube connected to the air filter housing from the engine block, but this can be prevented by removing the dipstick. . If air coming out of muffler then exhaust valve leaking. If air is rushing out of the dipstick tube then that would be worn/damaged rings or blown head gasket. Some air coming out of the dipstick tube is normal since there will be air bypassing the rings to some extent. Also air leaking past the valve can mask worn rings or head gaskets issues.

You will need to pull the head in the end but it will give you some direction to what to look for.

 

[F150Fan80]

You use your ears. If the air from the cylinder is coming out of the air filter housing then you have a leaking intake valve, not to be confused with air that could be coming out of the breather tube connected to the air filter housing from the engine block, but this can be prevented by removing the dipstick. . If air coming out of muffler then exhaust valve leaking. If air is rushing out of the dipstick tube then that would be worn/damaged rings or blown head gasket. Some air coming out of the dipstick tube is normal since there will be air bypassing the rings to some extent. Also air leaking past the valve can mask worn rings or head gaskets issues.

You will need to pull the head in the end but it will give you some direction to what to look for.

Sounds great. Thank you for the insight. My thoughts on the soapy water was mainly due to a really badly blown head gasket but the way you explained it makes perfect sense. I should be getting the tester tomorrow and should be able to test it tomorrow night. I will update once I perform the test. Thank you everyone for the help so far!

 

[Fish]

Have you tried the plug wire pulling test??

It doesn't cost anything, and could tell you a lot.

 

[F150Fan80]

Have you tried the plug wire pulling test??

It doesn't cost anything, and could tell you a lot.

Out of curiosity what would it tell me? I must be missing something. I know I have low compression in both cylinders. With it possibly running on one cylinder what else will it tell me?

 

[Fish]

Knowing which side is causing the problem would be nice, then you know which side to look at.
Could be a pushrod loose, ignition problem, who can know. But a simple test that takes less than 2 minutes, and will help you isolate the problem, plus it would cost you absolutely nothing.

 

[Fish]

Hell, it could just be a bad/fouled plug.

I once knew a guy that started to pull the engine on his truck, because the engine was "locked up". Turns out to be just a locked up alternator. Check the simple chit first.

 

[F150Fan80]

Hell, it could just be a bad/fouled plug.

I once knew a guy that started to pull the engine on his truck, because the engine was "locked up". Turns out to be just a locked up alternator. Check the simple chit first.

That makes sense. I will do that tomorrow morning. I will be getting at it first thing. I will follow up with the leak down test. This may point to other things being wrong however with compression that low in both cylinders I am not sure that I will yield any decent results by pulling the plug wires. Who knows, maybe I'll be surprised.

 

[F150Fan80]

Have you tried the plug wire pulling test??

It doesn't cost anything, and could tell you a lot.

I tried the pull test. It seems like one side is trying to start more than the other side. The side that had the higher of the compression readings was trying to start easier. I will be doing the leak down test next and seeing where that leads.