i just bought a 86 250r motor and the guy said it needed new main bearings. do you think i should attempt this myself or take it to a shop. i have a friend coming up for the weekend that could do it but not sure if if i'll have the parts in time. i got a clymers manual which does a pretty good job explaining it but wanted a second opinion on if i should try it myself. thanks
Nate

 

By "main bearings" do you mean crank bearings and/or rod bearings?
If you feel confident in yourself, go ahead. Also, most of the Clymer manual pics are of an 86. If you have the tools/time/parts you should be able to do it. Read the manual carefully BEFORE you start. Some special tools are needed for the job.

 

If you are really confident and have a lot of experience i would tackle it but if you are unsure the cases and main bearings need to be pressed precisely to work correctly, you could disassemble everything and have a shop split the cases and press the bearings in. Also if the bearings need to be replaced you may want to check for connecting rod to see what shape it is in

 

Splitting the cases and replacing the crank bearing is pretty easy. Jusy make sure you keep the tranny together.
ERIC

 

when taking out the bearing, put each case in your oven at 250-300 degrees, then the bearing just fall out, when putting them in, heat the cases again to 250-300 degrees and through the bearings in the freezer, the bearings will just drop in will slight tapping, but do it quick

 

thanks i think i'm gonna try it.
Nate