Performed the leak-down test this morning. Cylinders held pressure real well. Too well, it turns out. Meaning, a valve was not opening. Pulled the covers and found bent push rods on both intake valves. Placed order for new ones because once they're bent, they are soft, and likely to bend again. BUT, I wanted to get her running and rule out other issues, so I straightened the bent rods, re-installed, adjusted all to to proper clearance, and buttoned up everything. She started right up and ran real well.
Lessons Learned: Should have pulled the valve covers sooner for a look. It's so easy, but I was chasing all the electrical causes for a no-start.
Now for the reason, I believe, the two rods bent: The last task the tractor had was pulling a small sprayer trailer. I was doing that at very slow speed while spraying, with the throttle all of the way back in idle position. I believe I pulled her into the barn in that condition, and turned off the ignition.
Well it turns out that Kohler warns against that very condition. They say always have the throttle at mid to high RPM for shutdown. The purpose is to make sure the anti-backfire fuel shutoff solenoid activates to close the high speed jet and prevent the backfire.
So, I got lucky this time. It was frustrating to troubleshoot, but not expensive to fix. I view a bent rod as a good thing, over a hole in a piston, or broken piston rod, or a number of other things that would be much more expensive to fix.
So, case closed. Thanks for your interest and suggestions.
Lessons Learned: Should have pulled the valve covers sooner for a look. It's so easy, but I was chasing all the electrical causes for a no-start.
Now for the reason, I believe, the two rods bent: The last task the tractor had was pulling a small sprayer trailer. I was doing that at very slow speed while spraying, with the throttle all of the way back in idle position. I believe I pulled her into the barn in that condition, and turned off the ignition.
Well it turns out that Kohler warns against that very condition. They say always have the throttle at mid to high RPM for shutdown. The purpose is to make sure the anti-backfire fuel shutoff solenoid activates to close the high speed jet and prevent the backfire.
So, I got lucky this time. It was frustrating to troubleshoot, but not expensive to fix. I view a bent rod as a good thing, over a hole in a piston, or broken piston rod, or a number of other things that would be much more expensive to fix.
So, case closed. Thanks for your interest and suggestions.