Exup valve

[Ferrarikid]

Coud anyone tell me the size of the bush on the exup valve? I'd-od
I don't really want to spend the best part of £30 on one, as I might be able to find one at work the same size.

[Stig]

Theres 2 bushes
The smaller one is
9.90mm ID x 14.95mm OD x 3.91mm long

The larger one is
9.90mm ID x 16.87mm OD x 11.83mm long

Ideally they need to be phozi bronze or similar. I took the measurements as I intend to make some when I get a chance but times limited so they'll join the end of the queue of jobs. I've already bought the materials ..maybe a job for the winter eh?

[Ferrarikid]

Thanks for the reply,
Put me on the list for a set when you get a chance to make some.
Cheers
Lee.

[DonTZ125]

The Yamaha bushes are graphite. Perhaps the outer bush (on the housing cap) could be oil bronze, but the one in the pipe itself really should remain carbon. It may wear faster, but -once worn - the only way I could figure out how to remove it was to smash it to shards.

[Stig]

Don, the one in the main cover if definitely some sort of carbon graphite as i put a oxy torch to one to help loosen off a stuck valve many moons back....it exploded in a puff of white ash. The other 2 on the far end of the valve shaft appear to be more "metal" based IMO

[Ferrarikid]

I managed to get some bronze from work, with the help of a drill and a file I now have a bush forthe valve and no rattles on start up!!!!

[Stig]

another reason the valve rattles is when the valve itselfrests against the stops in the chamber...taking up the slack in the cables helps remove this issue

Glad you got sorted

[Ferrarikid]

Thanks for that extra bit of advice Stig,