Reply To: Valve clearences – GT125
It’s a bit more involved, first rotate the engine using the time marks to tdc on the front cylinder write down the clearance of each valve then do the same for the rear. If any fall outside of the values then you need to remove the camchain tensioner, then the cam that needs adjustment, underneath there are upside down buckets using a magnet remove the bucket that the adjustment is needed, under the bucket is a shim you then work out from the size marked on the shim to what size you need to bring it back to value replace the shim with the right size, repeat this on the ones needing adjustment. Reassemble head using the service data regarding torques, timing marks etc. Rotate engine a few times back to tdc check values again, then repeat same process for the rear & your done. I will be honest it sounds really bad & complicated but it’s a job you can do if you take your time. It is an expensive job at the bike shop because of the time it takes, with coffee’s fags & mucking about I spend a morning doing it but I do tend to take my time.