SnowRidge
Elite Member
A couple of weeks ago, the Kohler in my PT-425 dropped the #2 cylinder's exhaust valve seat--again. This is the second time. The first was under warranty at 110 hours. This one was on me.
The last time I took the engine out and had it repaired at my local authorized Kohler dealer, who repaired it under warranty, but managed to break off a shroud bolt in the #1 head in the process, which they "forgot" to mention, let alone repair, but I digress.....
When the seat came out, it broke some stuff and dinged up the piston, as you can see. The exhaust rocker retaining bolt broke in half, and the exhaust pushrod was bent. Amazingly, the exhaust valve itself was undamaged.
I decided to see if I could repair the engine without pulling it. It turned out to be difficult, but not impossible. The hardest part was removing and reinstalling the intake manifold bolts without removing the blower housing, which can't be done without pulling the engine.
The valve seat didn't seem to be damaged, so rather than spring for a new new head, I decided to try and drive the valve seat back into place and peen the head to hold it. I then lapped the valves in and reassembled everything.
I wasn't sure if the lifter had been damaged, so I decided to replace both of them on the #2 side. (I had mixed them up.
) I also decided to replace both pushrods while I was at it.
I had a hard time getting parts, which kind of bothers me. Napa is supposed to be able to get everything Kohler. They have complete Kohler parts catalogs in their stores and on their computers. My local Napa guy worked real hard at it, but could not get me a single part, not even from the factory. Something seems very wrong with the current Kohler/Napa arrangement.
I went to the Internet and nobody had lifters. I did manage to get a head gasket kit and pushrods from J. Thomas. I finally got the lifters and rocker bolt from a small engine repair shop a couple of towns away. He had to order them, but they came in when he said they would, so I will be dealing with him in the future.
Anyway, it is back together and seems to be running fine. I was a little concerned that the peened spots might be hot enough to cause preignition. If it's there, I can't hear it.
Now that the PT itself is repaired, I have been able to use it to hold the brush cutter while I repair it, but that is the subject of another post.
The last time I took the engine out and had it repaired at my local authorized Kohler dealer, who repaired it under warranty, but managed to break off a shroud bolt in the #1 head in the process, which they "forgot" to mention, let alone repair, but I digress.....
When the seat came out, it broke some stuff and dinged up the piston, as you can see. The exhaust rocker retaining bolt broke in half, and the exhaust pushrod was bent. Amazingly, the exhaust valve itself was undamaged.
I decided to see if I could repair the engine without pulling it. It turned out to be difficult, but not impossible. The hardest part was removing and reinstalling the intake manifold bolts without removing the blower housing, which can't be done without pulling the engine.
The valve seat didn't seem to be damaged, so rather than spring for a new new head, I decided to try and drive the valve seat back into place and peen the head to hold it. I then lapped the valves in and reassembled everything.
I wasn't sure if the lifter had been damaged, so I decided to replace both of them on the #2 side. (I had mixed them up.
) I also decided to replace both pushrods while I was at it.I had a hard time getting parts, which kind of bothers me. Napa is supposed to be able to get everything Kohler. They have complete Kohler parts catalogs in their stores and on their computers. My local Napa guy worked real hard at it, but could not get me a single part, not even from the factory. Something seems very wrong with the current Kohler/Napa arrangement.
I went to the Internet and nobody had lifters. I did manage to get a head gasket kit and pushrods from J. Thomas. I finally got the lifters and rocker bolt from a small engine repair shop a couple of towns away. He had to order them, but they came in when he said they would, so I will be dealing with him in the future.
Anyway, it is back together and seems to be running fine. I was a little concerned that the peened spots might be hot enough to cause preignition. If it's there, I can't hear it.
Now that the PT itself is repaired, I have been able to use it to hold the brush cutter while I repair it, but that is the subject of another post.
