jinma 50hr head maint

YOu should be okay, I think.  I did  mine at about 75hrs, as I recall.  I pulled the valve train off and re-torqued each head bolt to the specs that Ronald at RanchHand Supply provided, then re-assembled the valve train and set the valve lash properly.  Been fine since, too.

This is a good time to check every other nut and bolt on the tractor – I found loose wheel bolts, and other places that needed tightening or adjusting after everything had “shaken in” for the first 75 hours. 

I concur with Rich. I did my “50 hr.” engine service at 100 hrs., although I did, and do, check everything else at 50 hr, intervals unless symptoms requre otherwise.