Kohler CH740 power issues.

[Fish]

Page 36.....

http://www.kohlerengines.com/engines/onlinecatalog/pdf/sm_24_690_06.pdf

 

[F150Fan80]

Looks like your engine has smartspark, I looked up your engine and it said that you did not, so I didn't suggest it.

That is very likely your problem

Didn't realize that I had Smart Spark either. This is the one that causes all the issues right? Isn't there a kit that replaces all that? I just replaced the coils too. Lol. Thanks Fish for the page number. Made it really easy to see. I'm guessing that I should just replace that since I'm already in it doing a tear-down. I was able to get the heads removed tonight. It appears that the head gaskets were intact and not leaking, guess I did do that repair correctly. :laughing:

I did take some pictures of the worst head and the inside each of the cylinder to show you all. The cylinders look like there isn't any scoring at all. I may have caught it before it got too bad. Lucky me I guess. Anywho, I'm hoping to get the case apart tomorrow afternoon and I would like to order the rebuild kit soon. Any suggestions on where to get that? I posted the link to the one place I found but not sure if you all have a better option.

 

[Fish]

I would just try to repair the burnt connections with a splice. Doing away with the Smartspark involves a new flywheel too.

 

[Fish]

I don't believe that your mower had any other problems, I would clean up the valves, and put it back together and run it. Have the valve heads redone, as that was likely the only spot that you were losing any compression, but even that was minor.

 

[F150Fan80]

I don't believe that your mower had any other problems, I would clean up the valves, and put it back together and run it. Have the valve heads redone, as that was likely the only spot that you were losing any compression, but even that was minor.

You think that’s where I was losing compression? During the leak down test it appeared that most of it was going past the rings. I don’t recall hearing anything past the valves. I could be wrong though. I figured since I’m this far I’ll install new rings and such while I’m in it. I had the cover off today to check the insides and there doesn’t look like there is much wear in anything. The governor looks good, as well as the oil pump and camshaft.

 

[ILENGINE]

From the cylinder pictures you can tell there is cylinder wear, and the pistons look like they would be able to tilt back and forth. Is there a ridge at the top of the cylinders that you can catch a fingernail on. The newer style thin rings tend to loose their sealing ability after very little wear. After you get the pistons out take one of the rings and slide it back down the cylinder and see how much gap there is.

 

[F150Fan80]

From the cylinder pictures you can tell there is cylinder wear, and the pistons look like they would be able to tilt back and forth. Is there a ridge at the top of the cylinders that you can catch a fingernail on. The newer style thin rings tend to loose their sealing ability after very little wear. After you get the pistons out take one of the rings and slide it back down the cylinder and see how much gap there is.

I’ll check that out tomorrow afternoon. Thank you. I’ll get off work tomorrow about 630 am and sleep a little when I get home. The afternoon will be spent cleaning everything up on the engine so it’ll be ready to go back together once parts arrive. I’ll either be ordering each part individually or find a kit.

 

[F150Fan80]

Looks like your engine has smartspark, I looked up your engine and it said that you did not, so I didn't suggest it.

That is very likely your problem

What problem is there with Smart Spark? I don't really know anything about it.

 

[Fish]

A wide variety of symptoms, extremely squirrelly and hard to diagnose, start and dies, sometimes on one side.
>You name it...
Usually due to a bad connection somewhere, usually a burned or corroded connection interrupts the power supply to the SmartSpark module, often just a bunch of corrosion at the back of a keyswitch or plug.

 

[F150Fan80]

Love what I am learning here. So do you think that my harness plug on the engine side could have been an issue Fish? Could it have messed with the control module at all? I'll look through the wiring diagram at some point today and see where that terminal that looks like it's seen some bad stuff runs to. I'll have to check out my ignition switch as well. Couldn't hurt to at least. Do those control modules go out at all? If they do, what are my options to repair that? I don't remember seeing that being available for my engine.