Yamaha TRX850 Enthusiasts Forum

Hi there, can anyone tell me if the inlet cam runs stiiffer than the exhaust, possibly due to running cooler so the tolerances can be tighter. Mine is harder to turn than the exhaust, all bolts are 10nm.

Smiffy wrote:Hi there, can anyone tell me if the inlet cam runs stiiffer than the exhaust, possibly due to running cooler so the tolerances can be tighter. Mine is harder to turn than the exhaust, all bolts are 10nm.

No not stiffer at all. Remove and start over! Sometimes the order of tightening the bolts makes a difference.

Edit: except when the cam operates one of the valves - or all three - that takes some force of course.

Have you had the cam out? I've just discovered that mine was binding. The journals were showing signs of wear, probably because of excess heat caused by constant cam/bucket contact; when I checked the clearances I couldn't insert my .05 mm gauge!!!

Let them sit for too long they seem to starve for oil on the inlet cyl 1 part of the cam journal.
A little wet n dry to re-dress the journal and cap but check you can remove all the buckets too.
When it Burr’s over it makes it difficult to remove the bucket so may need to tidy that up too.
Once you clean everything up, prime the oil galleys too that feed the cams.
If sitting for a while, get a syringe and push oil in via the bleed bolt on the end of the exhaust cam.

How’s your dads TRX goin with the new motor???