Two and a half months later... Well, hey, it's back up and running by July! This poor Kohler was doomed from the start. I was soo enthralled with the tractor, I didn't even give it a good once-over before I used it
Had I have just taken the air cleaner off, I would have never bothered to run the tractor without a complete teardown and cleaning. It was soo caked up with dirt and grime that there is no way it could have possibly kept its cool under ANY operational condition! In addition to what you see in the dirty pics, the inside of the blower housing was caked solid right up to the flywheel: no airflow at all. I finally got some shop time with my mechanic friend last Wednesday. We pulled the motor down to the block for a total inspection. Not a virgin engine by any stretch. Both pistons had been touched by a valve at some point (dropped a guide maybe?) and it appears that the heads and valves have been worked at least once. The breather was actually not clogged, but the filter was missing, indicating that someone had been in there. The cylinder bores were in pretty good shape, but the bottom 3-piece oil control rings on both pistons were obviously not doing their jobs. We hit the bores with a hone for just 10-20 seconds to break the glaze on the walls and then removed the old rings and cleaned out the lands in the pistons really good. A lot of coked-up deposits there, especially on the wide bottom land for the oil rings, so I'm guessing they may have been siezed and not sealing.Everything else spec'd out fine, so we installed the new rings (at $75 a piston
) and put the motor back together with new gaskets and head bolts where applicable. No service to cylinder heads or valves.
I've been cleaning and scraping and scraping and cleaning the past two days to de-gunk the bolt-on accessories and tins and get the tractor back together for the weekend. Used a half tube of JB Weld on the 'engineered materials' to glue the front clip back together. So far, it's holding. I went easy on the retainers this time when I reattached it to the frame. I went ahead and put two new magneto coils on it while the engine was apart. The coils can be suspect on these engines, and since I know it got hot, all the better to swap them out now. I also did the SamMac clean and re-pack of the steering and front driveshaft CV joints. Got it all back together around dinner time and I now have about 20 minutes of smoke-free run time on the motor! Tomorrow, weather permitting, I will take it down to the powerlines and sink it in some taller grass to seat those rings good.
I'll be completely satisfied after a good performance tomorrow. I still like the tractor a lot, and hope the 2nd outing will be much better than the first! Oh, yeah, someone's been in the rear, too.
