I have a craftsmen lawn mower with a kohler command 15.5 cv15s engine. When I try to start it it wont crank past the compression stroke. I have replaced the battery and cleaned all of the connections from the battery all the way to the starter. I can get it to crank by putting a jumper cable from my truck straight to the starter. I know from reading that the valves are not adjustable on this engine so I dont know where to look next. How do I check to see if the compression release is working in this engine? I believe its on the cam shaft internally but am not sure. Any ideas on how I can get this fixed? Im getting tired of jump starting it. Once its running it runs fine with no problems. If I happen to kill it while Im mowing it usually starts right back up with having to jump it.

Little help guys. Im going bald pulling my hair out trying to get this fixed.

Dennis

 

Since it starts when you jump directly to the starter it has me thinking it's a power issue. Are you certain that the battery is fully charged? I would also inspect the cables carefully and look really close at the ends where the lugs are crimped to the wire conductor inside. Maybe there is a bad internal connection from the wire to it's lug causing resistance.

 

Maybe I should change out all of the cables from the celinoid to the starter and see if that does the trick. That would probably be the cheapest thing to try first. Pretty sure the battery has a full charge. Put it on a trickly charger when I got it home.

 

Sounds like a compression release problem. That is usually related to valve adjustment, but I see you've looked at that and yours isn't adjustable.

With the head off you can see the exhaust valve being held open by the compression release, but to fix it I'm sure you'd have to go deeper into the engine, if it proved to be not working.

 

I havent looked yet to see if its opening a valve to release the compression. Would you happen to know if its the top valve or the bottom one. I think on a briggs its the top valve but not sure on a kohler.

 

The exhaust valve is the bottom one on a kohler CV engine.

 

How old is the battery and has it been maintaining as per the owner's manual?

I'd suspect the battery if it's more than a few years old and/or it sat for more than 3-4 months without charging it (newer batteries are much better at holding a charge over time than older batteries).

You should be able to take the battery to a lawn and garden shop and have them load test it (a battery can test as being "fully charged" while still lacking the amperage needed to crank the engine).