Topic: more Yoshimura secrets

[bwaller]

HB-1fan, would you mind taking a couple measurements of those pistons? I'm curious to know the compression height and total dome height.

Thanks

[MRieck]

kidnapping my own thread, but I'd say it has to come from his own will, would never ever try to convince ANYBODY, kid or grown up, to ride, would never want the responsibility if something happens.

If someone takes on riding by his own will then fine, I'll help and teach as much as I can.

Back to the subject of the thread, HB1-fan, were stil missing the piston pics! 

TG



 

Don't worry....I don't live vicariously through my children. It's weird in that they see...and have seen....so much motorcycle stuff they have become pretty much immune to it. They can do what they like as long as it is productive.....I'm helping quite a few other people out with their stuff.

[Bill/BentON Racing]

Amen brother,called Barbara @ Megacycle,left message,cam pics still coming,did look in Megacycle old book and saw they had a cam for 550 that intake opened @ 25* BTDC,I do remember Yosh cam spec was 26* BTDC.The new cam did not have a spec sheet. Bill

[MRieck]

Amen brother,called Barbara @ Megacycle,left message,cam pics still coming,did look in Megacycle old book and saw they had a cam for 550 that intake opened @ 25* BTDC,I do remember Yosh cam spec was 26* BTDC.The new cam did not have a spec sheet. Bill

Bill....I think Megacycle has every cam in it's data log. I know they have grinds that are very weird for the 750SOHC....very custom. They can provide anything you want. The Yosh spec can be different secondary to measuring clearance (though Megacycle and all Jap stuff was 1 mm (.040 or so).

[Drew75]

Here's the pics of the Yosh Isle of Man TP TT Cam B grind

Guys I think Mega Cycle may have this already covered - but I'm checking.

[turboguzzi]

Drew, the cam shape is all wrong, I can see it from a mile,

so obviously, you should sell it to me, cheap.

PM'ing you the address for shipping

I am sure you wil be glad to be relieved, right?

TG

[Bill/BentON Racing]

TG,Drew might do that,I just got him to post pics,I was installing his engine,Damn its a 5 speed,Wow,sure sounds sweet,But Z cam is mine,might deliver for a few laps on your ride,Drew stuck in a couple initials that did not belong,Yoshimura B grind Isle Of Man TT.Be interesting to see what Megacycle has and how much to duplicate? My turn to sleep well,See ya,Bill 

[HB-1fan]

Hey guys,
 Been gone since since thursday! This thread is really getting me inspired to get back on track. I will try to get some pics for tommorrow night. ?

Here's the pics of the Yosh Isle of Man TP TT Cam B grind

Guys I think Mega Cycle may have this already covered - but I'm checking.

What does the "B" mean for the cam grind?

HB-1fan, would you mind taking a couple measurements of those pistons? I'm curious to know the compression height and total dome height.

Thanks

I will take some measurements of the pistons , also!This TT cam has a spec sheet, I will copy down the info.

HB

[turboguzzi]

TG,Drew might do that,I just got him to post pics,I was installing his engine,Damn its a 5 speed,Wow,sure sounds sweet,But Z cam is mine,might deliver for a few laps on your ride,Drew stuck in a couple initials that did not belong,Yoshimura B grind Isle Of Man TT.Be interesting to see what Megacycle has and how much to duplicate? My turn to sleep well,See ya,Bill 

Bellcow! is it the elusive yoshi 5-speed? if it is, please please take note of the gear ratios,

if you already closed the cases, open them up again , that will not be accepted as an excuse :-)

Cheers,

TG

[bwaller]

TG,Drew might do that,I just got him to post pics,I was installing his engine,Damn its a 5 speed,Wow,sure sounds sweet,But Z cam is mine,might deliver for a few laps on your ride,Drew stuck in a couple initials that did not belong,Yoshimura B grind Isle Of Man TT.Be interesting to see what Megacycle has and how much to duplicate? My turn to sleep well,See ya,Bill 

Bellcow! is it the elusive yoshi 5-speed? if it is, please please take note of the gear ratios,

if you already closed the cases, open them up again , that will not be accepted as an excuse :-)

Cheers,

TG

  We're a heartless bunch!

[Rod]

Bellcow! is it the elusive yoshi 5-speed? if it is, please please take note of the gear ratios,

if you already closed the cases, open them up again , that will not be accepted as an excuse :-)

Cheers,

TG

have spotted this after starting new thread (HRC Clutch Basket) - I have a CR cluster and comp clutch basket from late 70's early 80's that I always assumed to be HRC, also in the box of trick parts that came with the bike were some 'weird' swan-neck inlets just like the Yoshi ones shown in this thread which were matched to a set of CR31's. I'm now wondering if all the trick parts including the transmission stuff are actually Yoshi, is there any way of differentiating from HRC? Did Yoshi make a special clutch basket?

[Bill/BentON Racing]

TG for you I would,But Drew's motor stock 750,his first engine had no 2nd,that was 5 spd I was referring to. However those trannies are out there,If I remember the 6 spd had something strange,no neutral detent? I have yoshi 5 spd for CR750,you got info on CR500R?,Link please,DB-1,Rings?,590 kit?,Time to search,check with old contacts etc. Bill

[bwaller]

Rod, I can't really answer your question about that clutch basket, wasn't really into the 500's back then. However there isn't one offered in my old Yoshimura catalog. It wouldn't be CB650?

[Bill/BentON Racing]

I will post up price sheet,it shows the trannies to be YH500(Pops stuff) and YHR500 to be the(RSC stuff),the trannies are listed under YH500 area,yet the CR box for 750s is listed under YHR750( RSC stuff),maybe Pops built the ones for the 500? The RSC stuff lists pistons,rings,and pins,I think the pins in mine are the RSC they weigh 10 grams less each.Also lists a magneto, point cam,mag cvr,and tach and cable.TT cam was 118.50,also offered polished and lightened int and ex valves,cam chain,31 CRs were 460.41as a kit w manifolds,and stacks I think.Speed has bike racing on3-7:00p.m., Bill

[Jerry Rxman Griffin aka MuthaF'er]

My Yoshi catalogue price list has many of the same items. It does have  stuff listed under YH 500 and YHR 500. Doesn't have anything listed as RSC however. Prices slightly higher. Lists the 5sp/6sp trannies, magneto complete, magneto, point cam fixed advance, magnesium cover for magneto as special order. I received it ~ 1976. The 2 pages for the 500 are hopelessly stuck together due to water damage however so I can't access them. Tried steaming without success so I can't help with that.

No clutch basket listed.

Jerry

[Bill/BentON Racing]

[turboguzzi]

finally the pistons!

the yoshi slugs have little dome, maybe 2 mm for the rised part according to HB,

good confirmation that the 500-550 dont really need much dome to get good compression.

valve pockets are deep for a really hot cam,

what surprised me a bit is that they have full skirt and are not slipper type like the yosh 500 that you can see in ttr's site.

the flat outside ring should work as a squish area against the flatened head that is posted earlier (where the 15 taper was eliminated). Would be nice to see how these sit in a built up engine in terms of decking though you'd have ot know how thick a gasket pops planned for it

they have three not-very-thin rings, which leads me to think these were also made for street use and not just racing.


More info flowing....

TG

[HB-1fan]

TG,
 The gaskets all measure around 1.36mm. Thats with a caliper across the fiber surface to the metal ring. I don't have a mic here where the gaskets are, to measure just the ring.
I just noticed yesterday that the 4200 piston kit in the catalog pages are slipper pistons with short skirts. Plus, one of the sets of rings are of the normal 5 piece type, and the other set look like the 3 piece ones with the slipper pistons in the catalog(double bonded oil ring) picture. I will lay them out and take some comparison pics.
 
Thanks again with the pics help!!

HB