ATC90 cylinder compatability

[RapidRick]

Are there any other cylinders that can be used to replace a stock cylinder. Perhaps from a trail 90? :wondering

Thanks for any help.

[shortline10]

Depends on what year 90 you’re looking for ?
The early us90 motors seat differently into the heads .
The ct90 should be the same if it’s the same era , I believe 1975-78 are the same 74 and earlier are different .

[RapidRick]

Thanks Mike, looks like it's a 1976. That opens up possibility. Looks like I might have a line on a"big bore" piston, and met with a buddy who suggested a CB750 sleeve and piston (LOL, they're probably pretty scarce).

Trying to finish up a Joker roller I've been storing for a very long time.

Thanks for the help.

Rick

[Joseph Farrow]

Rick find a CB550 cylinder. Those are the sleeves you need. You can find them on ebay for $50 to the door all day long. Standard bore is 58mm and can go out to almost 62mm.
The sleeves will press out with little effort. You will need to machine the outside and top lip but is a simple fix with a lathe. Way cheaper than paying LA Sleeve.

[big specht]

Does the cb550 pistons have the same pin size as the 90/110 engines ?

[Joseph Farrow]

The 90 uses a 14mm wrist pen. The 110 uses a 15mm pen. The CB550 and CB750's both have 15m pens. To use either piston you will have to modify the piston to work. The deck height is different and the skirt will have to be modified to use with a stroker.270785270786270787