Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 350 Talk => Topic started by: old smokey on September 09, 2009, 08:36:56 PM

Title: old failed rotary valve on GTR
Post by: old smokey on September 09, 2009, 08:36:56 PM

I removed this rotary valve from the right cylinder of my GTR back in 1986. No reason why I never threw it away, but since i still have it I'm wondering if anyone has suggestions as to why it cracked.
The photos aren't real crisp, but I think it shows enough of what happened. I didn't really know it was bad, I just happened to remove the covers and turned it over by hand and saw this crack.

Title: Re: old failed rotary valve on GTR
Post by: Jeff Bar on September 10, 2009, 09:53:26 AM

That is normal rotary valve failure, as the fail from flexing, therefore the fibers weaken in that fashion, just replace it, I would do both sides

Jeff Bar

Title: Re: old failed rotary valve on GTR
Post by: Bridgestone Man on September 10, 2009, 01:32:45 PM

I am not sure this is normal!  Looks like some foreign object went through the system, just my idea
Sam Keys

Title: Re: old failed rotary valve on GTR
Post by: old smokey on September 10, 2009, 08:52:06 PM

the side facing the cylinder (I called it the backside) has more of a look of flexing and tear, but the front side has almost a look of a machined groove that starts deepest by the opening and tapers out. if it was a foreign object it looks like it only made part of one revolution. I've never had the heads off or done a compression check, but it always seemed strong.