Engine swap help 01 A/C mountain cat 800

[Tmann]

I just purchased a used 800 with a big bore (863) kit. I know that my stock carbs, clutching (main and possibly secondary) will need to be tweeked. I think the bore kit is manufactured by CRP. Does anyone have any knowledge of what jetting, clutching changes ect. will need to be done? Riding between 3-6K ft. The 144 track has also been converted to the 16 in wide with anti ratchet drivers.

Also came to realize that I also have to go from a 30mm clutch to a 33mm. Does the larger PTO end indicate what year the mod engine might be?

 

[Idcatman3]

If it's just an 863, does it use stock cat 900 pistons? If it isn't ported significantly past what the stock 900 was, I'd just go with stock 900 jetting/clutching.

The larger PTO end just means it's not an '01. All 8/900s 2002+ had the 33mm PTO end.

 

[Tmann]

That's kind of where I was starting with my guesstimate for the carbs. I don't know about the piston size. Is there a way to check without popping the caps off the top. Don't want to have to deal with head gaskets if I don't need too.

 

[Tmann]

What weights are used in the 900 primary clutch? Need clutch with weights and spring or what to buy.