I need a cylinder for my 85 200x(mine is already bored 1.00mm and needs more, also has timing chain tensioner wells(where the tensioner sits)worn pretty bad.

I've read that the 81-84? xr200r? jug(from Jeff and Knowsalot)is the same can someone confirm this so I can get one?

How much power can the stock bottom end hold on my X?

thanks

 

Any year model XR200 or XR200R cylinder will work on your 200X except for the 1984 and 1985 R models. These 1984 and 1985 R engines used a RFVC head and the entire engine more closely resembles an XR250R engine than the other 200 engines of that era. This engine also used two carburetors...so there is no mistaken it for the other ones..even though the other visual differences are great also.

Remember that the XR cylinder has a stock bore of 65.5 and not 65 like the ATC 200 models, so be sure you don't end up with a XR cylinder worse than the one you currently have.
Also, the XR cylinder has the same cooling fins as the ATC185 and ATC200 [non-X] models...meaning the fins aren't as long as the ones on your 200X cylinder. The fins DO make a difference in cooling, but isn't a "have-to" unless you are building this thing with a large pocketbook or going crazy with the cylinder bore and compression.

As for the bottom end holding up, the weak spot is the transmission gears....mainly on the main shaft where it contacts first gear on the counter shaft. Not that it is a common problem on these bikes, because it isn't. It just happens to be something that I have seen more than once and both machines were well cared for...and had numerous mods done to them.