CMB 90/91RS questions

[Don Ferrette]

A friend e-mailed me about parts interchanges on the purple head CMB evo 90's & I need some assistance to answer him. What are the major differences between the current RS91's & the 90 Evo II mk2 purple heads? (latest version before the RS) He wants to know if he chooses to freshen up his Evo's what parts he can use from the RS91's. Will bearings, p/s, zimmerman disc, etc interchange??

 

[Bart Drieghe]

Hi Don ,

Bearings : yes

P&S :NO, different stroke

Disc : no

Head ( logically NO )

Conrod : if not mistaken, yes

Main diff between evo 90 and 91 RS :

Different :

Crankcase

P&S

Disc

Crankshaft

fronthouse

Hope this helps ,

B

 

[AndyBrown]

Almost nothing is interchangeble. The ball bearing and the wristpin clips. Maybe the rod.

Oh and the carb arm.

 

[Don Ferrette]

Thanks guys! Well if he wants to keep running those I guess he better stock up on parts .... if they're still available.

 

[Bart Drieghe]

Brandnew :

http://cgi.ebay.de/CMB-90-15ccm-EVO2000-NE...1QQcmdZViewItem

BrandnewEVO90

 

[DaveMarles]

Andy. the carb arm will be the same forever. I guess they have a lot in stock. (unfortunately) :angry:

 

[Bob Finn]

Actually, the latest engine I got has a new heavier arm!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[Bart Drieghe]

No wonder Bob , it has more power too

Makes complete cmbsense !

B

 

[Mike Broad]

No one mentioned that the crank case bolts can be modified to fit!

Mike Broad

p.s. I believe the induction discs are the same

 

[Buckshot]

No one mentioned that the crank case bolts can be modified to fit!

huh? Modified to fit what? h34r:

-Buck-

 

[Mike Broad]

No one mentioned that the crank case bolts can be modified to fit!

huh? Modified to fit what? h34r:

-Buck-

Any of the 90 engines from 1984