Yoshimura R&D Superbike

Not sure on the cams but I'm guessing pretty mild lift since the head isn't clearanced.

I agree that it doesn't seem right to have the extremely heavy stator and starter on the bike - maybe it's so high compression that kicking it over would be a pain? If that were the case, I still don't know why the kicker wouldn't be removed. Though in all the vintage racing pictures of AMA Superbikes [I'm assuming this was for the AMA Superbike series, but in reality I have no idea what series it was built for], the stator, or at least the stator cover, was mounted, occasionally the bottom was shaved for more left cornering clearance.

Web Cam is right down the road from me - I wonder if I could stop by some day and have them map out the profile/duration/lift to help identify it. This motor did not come with a cam cover and I don't know if the cam cover is more limiting than the head. What is the maximum lift before having to clearance the head?

It was getting late last night so I didn't want to get elbow deep in carbon and grease, but I'm hoping to pop the head off this weekend to get a better picture at what's going on with the pistons, bore, as well as head. It's obviously only a single plug head.

79MKII wrote: Not sure on the cams but I'm guessing pretty mild lift since the head isn't clearanced.

My cams are .395 lift and the head needed clearance....the lobes look tall compaired to stock.

funny they went shim under?.....wouldnt have to worry about spitting shim....maybe? less chance of a minor engine failure maybe.

looks way to clean inside.....low use for sure....outside looks like chit.

The number I've seen is right around 380 or so, but each setup is slightly different.

34 years o so since they tuner had it as a E.L destined mill...folks may have run it on the street, dinosaur raced it as i was told, or just might have left that stuff on to be able to restart a crash/stalled bike and finish the race....

either way if the tranny is kawi close ratio factory one...that would be worth it...the reason he told me they used the early Z1 cases was that they were thinner and the motor weighed less...goes against the extra street gear....so much gets lost or re-told wrong as things change hands...I had one race team owner from back in the day stand there and tell me he had no race team in 79...which there was and the photos came later to prove my story and disprove his.....

The sum is that the metal parts dont lie or forget and what you got is a killer piece of that era....

just put the cams in and check them out with a degree wheel.

Alright, I couldn't stand the anticipation, so I pulled the head off tonight.

MMS_6687 by mmsmithgall , on Flickr

MMS_6688 by mmsmithgall , on Flickr

MMS_6717 by mmsmithgall , on Flickr

MMS_6696 by mmsmithgall , on Flickr

MMS_6697 by mmsmithgall , on Flickr

MMS_6698 by mmsmithgall , on Flickr

MMS_6703 by mmsmithgall , on Flickr

MMS_6700 by mmsmithgall , on Flickr

MMS_6708 by mmsmithgall , on Flickr

MMS_6710 by mmsmithgall , on Flickr

MMS_6713 by mmsmithgall , on Flickr

Is it me or do all the pistons sit in the bores the same level.

Kz1000 I have 1 and 4 are up while 2 and 3 are down....bigtime differance????????????

Dont know about Z-engines....could be an early version crank???

Frankinfreak crank maybe???

Could be a multi-firing engine....sweet

4TheKZ1000 wrote: Is it me or do all the pistons sit in the bores the same level.

Kz1000 I have 1 and 4 are up while 2 and 3 are down....bigtime differance????????????

Dont know about Z-engines....could be an early version crank???

Frankinfreak crank maybe???

Could be a multi-firing engine....sweet

Haha sorry for leading you on... the crank is anywhere in its rotation, not TDC. I bought the motor without the cams attached, so I just popped the head off wherever the crank lay.

Good Fortune!

4TheKZ1000 wrote: Is it me or do all the pistons sit in the bores the same level.

Kz1000 I have 1 and 4 are up while 2 and 3 are down....bigtime differance????????????

Dont know about Z-engines....could be an early version crank???

Frankinfreak crank maybe???

Could be a multi-firing engine....sweet

:whistle:

in any flat crank four cylinder motor, pistons will be the same level when pins are at 90 degs ATDC

So, I guess any street cred I had is gone....... :blush: :blush: :blush: :blush: :blush: