Wanted!! 300ex left case half.

[Ryanwolfe911]

Desperatley need a 300 ex Left(shifter) side crank case half. Can be from any year 300 ex, as long as it's not damaged. Minor scrapes are ok. 250x cases WILL NOT WORK. The bearing bores for the crankshaft bearings are way too small. And there is no provision machined into the case for the starter reduction gear shaft.

[CHUCK DUNN]

:rolleyes: pmed ya

[zell250x]

is the 250x and the 300ex case bolt pattern the some? im planing on putting a 300 crank in my 250 and im trying to seee what all i need to do to make this work.
thanks

[Ryanwolfe911]

Read my above post again. you cannot put a 300ex crankshaft ina 250X. 300ex crankshaft bearings are much larger than the 250X ones, and also , the entire oiling system is different. Just about the only thing you can do to have the best of both worlds, is to rob a right side clutch cover, kickstarter assembly and decompression assembly froma a 250X and put it ina 300ex engine. But as far as similarities between engines goes, that's about it. They are COUSINS, not the same quad.

[Ryanwolfe911]

I didn't get no PM from ya. Send it again please

[zell250x]

i no that the 250 crank wont fit the 300 case but i was planning on put the 300 crank with the 300 left case so that the bearing would fit. if the bolt pattern is the same then it should work. but im not sure about the oil system work.

[Ryanwolfe911]

Both the bearings are the same size dude. If it wouldn't fit in the left case half, it's not going to fit in the right side either. Do you get that? The only way this would work, is if you could put 250X crank bearings on a 300ex crankshaft, but even the inside diameters of the bearings are different. Trust me, I have rebuilt many,many of these engines in my shop. It cannot be done without major modifications of custom parts. Why the hell do you want to do this anyway? I think a 250 engine is much better than the 300ex, due to the shorter stroke. It revs out much faster, and can be modified to beat the pants off any stock engined 300ex with minimal money.