A forum for owners of Yamaha TTR250 trail and enduro bikes!

TonyB479 · Member

Cam Covers

TTRfan · Super Guru

Hi Tony - sorry to hear of your problems cry

Are all the cam caps cracked? That would seem odd. The only cause of that would be a slipped or broken camchain (or re-assembled wrongly) allowing the piston to impact on the valves, However, this usually results in bent valve stems and not damage to the caps.

The caps aren't sold separately as, in the manufacturing process, they are bolted to the head that they are going to be used on and line bored in situ. This means that there might be slight differences in alignment if you were to obtain caps from another head. It may or may not be a problem but your difficulty will be finding someone willing to split their caps from a head. Maybe try a "wanted" advert on here in the appropriate sub-forum?

The dowels are available new from a Yamaha parts dealer - part number 99530-14016 - cheap enough wink

Brian

ttboof · Super Guru

I made a xr 250 head up out of three old heads mix and matching parts after a mate siezed it

IT rattled a lot but worked fine for years , id give it a go just watch out that they arnt tight on the cams if so a bit of a cean up of the surfaces woild be nessary

TTRfan · Super Guru

Thanks Les - perhaps I was being too gloomy disbelief

If different caps are fitted and the camshaft won't turn when the caps are torqued down then there is a (time consuming) remedy - see here - that I have used previously to good effect. It is a very "gentle" process and won't work if the replacement caps have an obvious step on the joining faces.

Brian

roary20011 · Member

hi i have covers of old head and dowels

let me know if you still need