Older Kohler CH25s twin, cylinder head trouble

[Modrob]

I had my PowerTrac PT425 finally running again for a period, and then it broke again. Ended up finding cylinder head #2 exhaust valve seat had come loose and boogered up a couple of areas around the seat location. I started trying to find a replacement head online and having trouble (more on that later) I thought why not try and see if I could hobble this thing back together in the meantime. The seat wasn’t damaged. I took a dremel flex shaft and deburred the seat area and got the seat back in fine. Getting the damaged material back in shape again left a fine sliver of a crack to the outside of the seat in a couple of small areas. I then took a nail set and peened around the area surrounding the seat, followed by a small punch. And more deburring with the dremel tool. It seems to have sealed up fine. Reinstalled the head after ensuring valve assembly was fine and gave it a whirl. It fired up fine and ran good as new. (Don’t have a lot of faith in it holding up for long)
Anyway, trying to find a replacement head and not finding a match. The number cast on the head is 24 494 04 and “2” at the top between the rocker arms. Can’t seem to find any heads that list superseding that number…
I’ll attach a pic of the “repair” for your laughing pleasure (the pics are before I did the peening)

 

[RandyT]

Will need the spec number from the engine tag to narrow down which head part number it is. And i would of took a center punch and peened around the valve to protrude the aluminum over the edge of the seat. Numbers cast into head doesn't mean anything outside of the factory. Other than the 2 which is the number 2 head.

 

[Modrob]

PowerTrac company told me the spec number was 68500…(the engine tag is worn off so mostly illegible)
I did use a punch after the nailset divots, and I believe those two processes might have sealed it up. I had to run out of town for a few days so I was only able to just fire it up for a few minutes…when I get back I’ll give it a better test…

 

[Williy]

odrob check here maybe you can find what you need:

Kohler CH25s twin, cylinder head 24 494 04 - Google Search

willy

 

[RandyT]

The replacement #2 head part number is 24 318 201-S supercedes to 24 818 02-S for the 68500 spec engine.

 

[Modrob]

Got back in town and fired it up…ran great, so I put it to work doing some grading for about an hour…no problems at all. Oddly, when I cut the key off and it dies down, right near the end it kinda acted a little rough for a second or two…this time I didn’t throttle down and let it idle at low speed for a minute or so. Usually when I don’t, after it stops running, in about a second it’ll “pop” out the exhaust.