CMB 90 case

[David Ashcroft]

Question?? I have a older style cmb90 ( gold head)I got and want to adapt it to a outboard adapter I am thinking of buying ,,the adapter was made to fit a purple head 90evo ,,are the cases the same ? Will my bolt pattern be the same as the purple evo?I fairly sure they are but just checking with anyone..

 

[Andy Brown]

Silver, gold and purple are the same on the output shaft side.

 

[David Ashcroft]

Great thanks Andy for info.

 

[David Ashcroft]

What mods do I need to do to my older gold head cmb90 to fit more modern 91/101 piston/sleeve in my case?

David

 

[Andy Brown]

Just need to turn down the diameter a few thou. The new 91 and 101 have smaller bore than the old 90 and 100.

 

[Koban Rado]

I have some parts for CMB yelow dead.

 

[David Ashcroft]

Just need to turn down the diameter a few thou. The new 91 and 101 have smaller bore than the old 90 and 100.

Andy I don't understand your answer,can u elaborate ,

David

 

[Jeff Lutz]

Just need to turn down the diameter a few thou. The new 91 and 101 have smaller bore than the old 90 and 100.

Andy I don't understand your answer,can u elaborate ,

David

. Not much most can do. Because the new sleeves are smaller (by design) they will not fit your gold head . I'm not saying things couldn't be made to make the parts work, but its more trouble then it's worth.

 

[dwilfong]

The newest EVO 4 bolt gold head has a smaller OD on the sleeve than the old gold head.

The RS red head is in between both of them.

Best to get a new gold head 4 bolt head eng as the parts are available or a RS red head as there are still parts for them also.

also the RS case can be board to fit the new EVO gold head 4 bolt head liner.

If you want to keep it running after the parts become unavailable in the future for the RS.

 

[ALLAN YUEN]

I did check

NOPE Fit to RS( red head) from P/L RS EVO ( 2014 gold head) won't work . I believe that RS (red head) piston/sleeve will go out of phase in few year but need to go mill machine on " RS"( little big bore) crankcase so will fit from new RS EVO Piston/sleeve or RS EVO only sleeve(liner) need to cut little small bore by lathe machine then will fit to RS crankcase orignal in future ( just in case)

 

[Andy Brown]

Just need to turn down the diameter a few thou. The new 91 and 101 have smaller bore than the old 90 and 100.

Andy I don't understand your answer,can u elaborate ,

David

David, I am sorry, I miss read your question. I thought you were asking about putting the old head buttons in the new sleeves. Everyone has answered....nothing can be done about putting new sleeves in the old cases.

 

[David Ashcroft]

Ok thanks fellas...

David