90 Yamaha G8 J38


New Member
Motor would not start, upon investigation I discovered my cam was broken. Upon further investigation I determined the cause to be slop in the crankcase housing where the cam resides. therfore the case is no good. My research found the replacement cost for a J38 engine is very exspensive. I'm thinking of a conversion to a bigger and more cost affective option. Has anyone done a conversion, Thoughts & Ideas please


New Member
That is very common with the J38. I have rebuilt many of these motors. You can repair the crankcase by welding up the damaged hole or install a bearing in the crankcase like they did on the counter balance. I have the jig to machine these cases. I also have some good used crankcases that I can sell for about $200.00. Call me at 626 536 4151 and I can hel[p with your challenge.

Valcat, Inc
Glendora, CA