King Kat piston damage - pic

[hunterdon]

King Kat piston damage

04 KK mag side piston damage on intake side - some damage on exhaust side too but not as much. Sled siezed less than 100 miles ago. Replaced both sides and installed bigger mains and new zr needles and raised needles 2 positions. premixed the first tank of 91 octane. Was acting rich and egt was not above 900 today when it stuck 1/2 mile from truck. We have been very carefull to let it warm up good. Does this look like a lack of oil or lean condition?
I will try to upload pics later.
Having issues uploading pics damnit!

 

[Tmann]

Did this happen while crushing the trail running your sled between 4500&5500rpm? Are you goosing the throttle every couple seconds while on the trail? These run hot due to timing from the factory in the mid range. Jetting doesn't seem to really help it. My sled had 2 motors installed under original warranty due to burn up on trail before it hit 300 miles by the previous owner. I bought it and have over 1k on it and no issues. Just burp the gas every 5 seconds when on the trail or occasionally flip choke to first position especially at lower elevation and cold temps. This may be old news to you and is based on not seeing the pics. Sorry about the damage

 

[hunterdon]

Thanks for the reply - I found the culprit. The crank seal and ALL the crank bearings are toast. We are aware of the midrange thingy with this motor thanks to previous posts on this forum. Sled has run flawless for many miles until this season.- I just did not dig deep enough on the first piston episode. Now looking for a rebuilt crank. Thanks again deadsled.