81 atc250r cylinder swap

[TRIPOD guy]

Will a 78 cr250r cylinder fit on a atc250r case.

[TRIPOD guy]

Does anyone know if the stud spacing is the same or close enough to modify on these two cylinders. My friend has the late 70s 250 bike engine with stock bore. My 81 atc250r is .080 over the cylinder is trashed. Don't have a machine shop in my area to put new sleeve in cylinder.

[yaegerb]

Does anyone know if the stud spacing is the same or close enough to modify on these two cylinders. My friend has the late 70s 250 bike engine with stock bore. My 81 atc250r is .080 over the cylinder is trashed. Don't have a machine shop in my area to put new sleeve in cylinder.

Fill out a form and mail it to LA sleeve. They can put a new sleeve in and set you back up on OEM bore. You can also get a piston kit.

[TRIPOD guy]

Pick up that 78 250r cylinder look real good. Going to pull the cylinder off the 81 atc250r and hopefully it bolts on.

[TRIPOD guy]

Not a direct bolt on! The holes are off by 1/8 side to side and 1/16 front to back. Going to try to make it fit got nothing to lose anyway and the cr jug has a bigger intake manifold.

[TRIPOD guy]

The cylinder sleeve is moved forward 3/16 so I'll have to get that right before I start grinding on stud holes.

[TRIPOD guy]

Just incase someone is paying attention to this I'm going to get the atc250r gasket and use it as a template on the elsinore cylinder. Been snowing here in northeastern arizona so I've been out snowmobiling alot and haven't had the time to get to this project.

[TRIPOD guy]

Got a atc cylinder that's a stock bore so not going to modify the cr jug to much work once I got the new gasket and tried to line it up with the direction it needed to sit