Yoshimura cams - again

[Anonymous]

I have bought a GS1000 engine and the cams are marked "POPY" which means they are Yoshimura I think from reading previous posts. The only other mark on the ex. camshaft is a "B" stamped on the right end. Can anyone tell me how to identify them further eg. stage 1 . I have read the previous posts but must be a slow learner, so please keep replys as simple as possible. The engine also has an unidentified big bore kit and "popy" oil cooling system. Thanks for any help.

[simon lambert]

Pop Engine

Wow what a find..
anything else distinguishing on the engine?
Straight cut gears etc?
Is it an ex race bike or engine?
Regards Simon

[Anonymous]

The engine was bought as a complete bike. It was fitted in a Harris frame, which I think is an early one from what I have found out so far on the net. The sump bolt etc. have been drilled so I assume it has been raced at some time. I can't say much more at the moment as I have stripped the engine and put it in boxes and not had much time to look at it again.

[robinjo]

Do you have any pictures of the bike?

[Hap Call]

You will probably have to get a dial indicator, a degree wheel, and a couple of v-blocks and check lift and duration yourself or have a quality engine shop do it.


Hap

[Anonymous]

I will need the specs for the different types of cams though.

[Billy Ricks]

At least in the '90 Yosh catalog they only listed Stage 1 cams for the GS1000. No specs though. If the pistons were from Yosh they could be Cosworth.

[Anonymous]

I have the cam specs for the old stage I and stage II cams but I cannot help identify what you have .

Yoshimura used more duration on the intake cam than the exhaust to increase midrange on the two valve motor . The exhaust port design and porting wizardy allowed for this w/o loss of top end power .

The race motors used cams larger than the stage II offered to the public .

On another note I have a couple of great pic of the 1000 racer but do not know how to post them since I don't go to or have a hosting site .

I would email them to anyone interested . The bike has some neat one off pieces on it to include a cool exhaust can 8)

[Anonymous]

Thanks for the replys so far. Re Billy Ricks - do you mean cosworth made the pistons for yoshimura? Re TwinCam - thanks for the pics. I've sent you a pic of the same bike. Anyone else got any useful info?

[Billy Ricks]

Re Billy Ricks - do you mean cosworth made the pistons for yoshimura?

I know for certain the mid '80s to early '90s was Cosworth. I have a set of Cosworths for my bike. They aren't Yosh Cosworths though. There is a guy close to where I live that had the Cosworth U.S. distrbutorship. He was supplying custom Cosworths for Britt Turkington when he was riding a GS750. I got my hands on a set of unused pistons. They'll be going in someday. If what you have are Cosworth the name is cast into the piston bottom.

[runrx02]

I know this is an old topic...but could someone post the specs for the Yosh cams for the gs1000? Thinkin about having cams ground for my 1000 project and figure that would be a good place to start.
thanks