Splitting the bottom end.

[eprovenzano]

I just wanted to thank rubbersdown for the write up on the engine rebuild. http://www.exriders.com/vbb/showthread.php?s=&threadid=449203 I've discovered a bad rod bearings and decided to replace the crankshaft. I followed the post of rubbersdown step by step and was able to split the cases and replace the crank. I replaced the main bearings, timing chain with a new one from a CRF450. I will also replace the timing chain tensioner and have the piston bored to 4 overr.

Without the writeup I doubt I would have repaired the quad. I studied the writeup rubbersdown did and felt as though I could handle this. What I found is splitting the cases was not nearly as difficult as I expected.

Once again thanks for taking the time to document splitting the cases. I really appreciated it.

[82toyota]

just asking but when u split the cases.....why u not clean the out side of the cases just asking but thanks for post the pic i never seen the need side of the motor before......on a 400ex.....

[eprovenzano]

I had to split the cases to replace the crankshaft. We've seized two pistons onto the piston pin. There was too much play in the rod bearing causing the piston pin to fail seize to the pistoncausing the piston to fail I've done top ends before but this is the 1st time I've split the cases.

As I stated earlier if I had not seen the write-up I most likely would have parted out the quad. Now it's going back together (with a few upgrades) and will be on the trail for many more years.