stock cylinder sleeved to 310 ? good or bad

[catch me if u can]

is a stock 1987 cylinder that has been sleeved to be a 310 with head mods and cool head anygood or would it be better to get a pro-x cylinder can i just have the pros and cons of the sleeved cylinder set up thank you

[superevil]

Pro x cylinder will be way way better.
I dont have first hand experience but i have read on here that the big bore stock cylinders arent worth it.im sure someone on here is happy with thiers but i have read from some very knowledgeable people on here that it isnt worth it

[quadracer87]

i heard they arent that great. its better then a stock 250cc jug though lol

[siderbox]

lilredridenwood had one. It worked ok. I'm with superevil, a ProX would be better in the long run.

[drag lt guy]

well the disadvantage with the big bore sleeve in the stock cylinder is that you'll loose alot of transfer area and that means loss of top end...

[morse250r]

ive seen guys get more porting out of a stock cylinder, 295 is what it really is pro x jugs the water jackets are real close to the exhaust ports and make it hard to get alot of porting out of them more in the lines of a drag port, if your hard bent on getting a new cylinder i wait a month or 2 and look into a puma cylinder its going to be a whole new design and update from the almost out dated pro x

[catch me if u can]

so is the relabilty and performance about the same

[catch me if u can]

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[catch me if u can]

would i need a spacer since i have a 88 motor and this is a 87 head and is performance and relabilty about the same as a pro x cylinder

[fulltiltrider]

Performance will not be the same. A prox's port layout is way different than oem. Prox's have a tripple exhaust port. Plus Ive heard of people having cooling issues on a 310 sleeved oem cylinder