Yamaha YZ85

Mark Watkins · Joined: 18 Jul 2001 Posts: 545

While at my local Honda/Yamaha dealership in beautiful downtown historic pastoral Redlands, I spied a 2002 YZ85 sitting in the showroom. Supposedly this was the year Yamaha was to change the motor.

What I observed.

1)same barrel and head
2)same water inlet and outlet locations
3)NEW clutch cover case with a removeable inspection cover for the clutch (cool!)
4)cases LOOKED new, but I could be mistaken.They appeared even more compact than the tiny YZ cases we now use
5)an interesting item was the pipe. Same basic location and configuration, but it was noticably wider in the dwell section, nearly as wide as a K4. Could this mean more exhaust port TA?
6)flatslide carb (is this new?)

Anyone have any official data on this motor?

Mark

David Mayhew · Joined: 31 Jul 2001 Posts: 209

The motor is completly different. Not sure how it is going to run yet, but it is way different.

David Mayhew

S. Clark · Joined: 18 Jul 2001 Posts: 32

Is 85cc legal yet?

Rick Blood · Posted: Tue Aug 14, 2001 7:23 am Post subject: Yamaha YZ85

David,
If anyone would know it would be you.

Tim Blaney · Joined: 18 Jul 2001 Posts: 1127

quote:
Originally posted by S. Clark:
Is 85cc legal yet?

Right now, no.

Mark Watkins · Joined: 18 Jul 2001 Posts: 545

I did a little more huntin' and I found out:

bore/stroke 47.5 x 47.8
new tranny shift shafts and selector
28mm flat slide Keihin(sp) carb
new clutch
digital ignition
new porting for more mid-high

Hmmmmm Yamaha might have a player here.

Oh, and from my observation, same pipe spigot deal.

Mark

Ken Freitas · Joined: 17 Aug 2001 Posts: 7 Location: CA

Mark,

Completely different motor.

Barrel Head: Different
Water spots: Same
Clutch Cover: Cool
Exhaust: We are running the same exhaust (RLV)exhaust. It looks good on the dino
Carb: New, We are working on getting it up to the other carbs But it comes with the engine so that cuts down on the cost.

All in all the engine has some major advantages with the digital ignition. Should have more info on that soon.

Not sure if the rule change has gone through yet but it will be legal next year.

It is 84cc same as the Kawi and Suz only one not there yet is the Honda.

Ken

John Clasen · Joined: 04 Aug 2001 Posts: 563 Location: San Marcos, CA

Ken, just a little reminder about the site rules. Unless your full name is Ken, please go back and complete your registration.

Next, in your post you state that the 84cc Yamaha 2002 will be legal next year. Since your idenity is a mystery, can we assume you work for one of the big three (SKUSA, IKF, WKA)?
J.R. Clasen

P.S. Mark, the displacement works out to 84.704cc

[ August 19, 2001: Message edited by: John R. Clasen ]

Ken Freitas · Joined: 17 Aug 2001 Posts: 7 Location: CA

John,
Opps, I'm new to the site, hope it's fixed.

Nope not with any of those organizations. I have been lobbying for the legality of this engine for some time now. Can't say for sure, but I believe the skusa's intent for the 80 class is to use stock engines. I hope this is true. I'm sure they won't exclude an engine maker that is as active in karing as Yamaha.
Ken

Ken Freitas · Joined: 17 Aug 2001 Posts: 7 Location: CA

FYI,

The 2002 Kawi KX85 Bore 48.5 Stroke 45.8=84.6CC
The 2002 Suzuki RM85 Bore 48 Stroke 46.8=84.7cc
The 2002 TM85 Bore 47 Stroke 51=88.48cc
The Yamaha YZ85 as above 84.7

Still only Honda with less than 83. If you want to run any new engine next year and the rules stay the same, you would have to run a Honda.

I think we can expect a rule change, possibly to state OEM displacement.

Ken