I am so greatful my Kohler stuck a piston...

[EricR]

Because I would have never torn it down and found THIS!





No idea where the pieces were, nothing but some dried up varnish stuff in the bottom of the case on that hole. But it does explain a thing or two. I would have to adjust the air screw on the Mikuni to get it to idle when warmed up. Then if I came back, started it up cold, without lowering the air screw, it would idle so fast it would take off at about 5 mph. That bearing had enough slop in it to make the PTO side suck air around the seal I would bet.

It's an NTN bearing with a number on it, should not be that hard to find and the mag side looks good but I will likely replace that too.

So far looks like I need a PTO piston, rings for both sides, a complete gasket set and seals, outer crank bearings, a fan belt, a plastic recoil pulley and that seems about it. The jugs cleaned up with a hone decently.

[400brian]

That is why we harp on about the seals. And you get an eye ball on the bearings when you pull the old ones out, even if you don't split the case.
Sounds like you have a handle on it now. Good job!

[EricR]

Now mostly back together with this- after looking it over, it was the bearing coming apart and the shrapnel dinging up the piston on that side- there was absolutely no aluminum transfer from the piston skirt etc to the cylinder wall. Now I do not know what made the bearing fail or if in fact it was a latent thing lurking. Plugs were always a dark tan.

I got a NOS piston, new SKF bearings and a seal kit from John Schavemaker, and a new head, fan belt and some recoil parts from GPI in Michigan. I probably could have re used the head, but it had some dings in it that I felt could create a hot spot for future detonation. For 16 bucks NOS I did OK.

The right piston and rings were fine so re used. I did a light hone on the cyls to take care of some little scratches etc.

The fan bearings sounded dry, before I spent money on them I pried the dust seals back, the balls etc were perfect but the bearings were a tad "dry" so I packed some wheel bearing grease in, nice and quiet now.

I will pressure test the engine when done and make sure no air leaks. Then I have to pack it in a bullet proof method and ship it to MN from GA. That's gonna hurt! $$

Going back for Waconia!

[sledhead16]

See ya at waconia!