YZ to WR engine question

[YZ400EX]

Ok so here is the story.. I recently sold my Hybrid with a YZ400 engine to my cousin.. on his second trip out on it he pulled the hot start and left it on and went rippin.. it didnt take long for that lean engine to drop a valve, put a hole in the piston, mangle the head, bent the rod and cracked the cylinder.. Lots of damage!!:D Well he just bought a WR 400 engine off of Ebay with a YZ 426 rod, cylinder, piston and a few other 426 parts.. I think with this being the wider gear ratio it will better suite what he needs to do with it.. Does anyone know much about these motors at all in a hybrid?? Doesnt seem to be a very popular build.. is it just because it isnt an MX geared motor?? Anyone know how the tranny's of this motor will hold up in a quad?? Anyone know of anything I should know about other than the obvious (different gearing and lights can be hooked up to it)??? Thanks

[ss440ex]

Doing some reading on www.thumpertalk my anwser some of your questions...

MAN!! he trashed that YZ engine,Huh?

[YZ400EX]

I did alot of reading on there and it didnt really answer any of my questions about using this engine in a hybrid.. thats why I came here..:D

Yes he tore that engine up.. cheaper just to buy a new engine than it was to fix all the damage..:mad:

[YZ400EX]

Well here is an update to what I have learned of the differences.. nothing, but the stock swingarm bolt on a WR is much bigger than a YZ and the pieces that the bolt slides through must be used from the YZ motor in the WR.. Also the engine that we bought that was supposed to have been a perfect running engine ran for about 2 seconds and had such a huge knock in it that it was scary.. Dont know whats wrong with it yet, but definately something is..

[CrackerboyLV]

I have the WR Gears in my YZ case. I like the 5 speed for racing WORCS, if I only used it for MX I would have stuck with the 4 speed. It would be nice to be able to run lights at the dunes. I'd keep the WR if you can make it work...

[ss440ex]

I believe the timing of the exhaust cam is different between the yz / wr.