crank install

[87250rxrider]

hey,

i've had to strip my entire yz426 engine down due to problems, which included splitting the cases, and taking the crankshaft out. i'm wondering how i go about installing the crankshaft again? the manual says that a tool is needed but i was wondering if there is another way to go about installing it back into the case?


thanks,
-Ryan

[250X_project]

I don't know much about the YZ426, but I don't see why it would take any more tools than what you used to take it out. You should only need an impact, sockets, wrenches etc., but I assume you used these to begin with.
I would recommend new main bearings while it's apart though. Rod bearings as well if can be afforded.

[dork]

you should use a puller to install so it doesn't go out of true. i made my own. get a nut that fits the left side threads, and weld it to some pipe long enough to clear the crank threads. then weld a bolt or a nut with a bolt to fit it in the end of the pipe. thread that onto the crank. then get a large piece of pipe that will fit against the inner crank bearing race, and a washer that will fit over the other end. then use a nut on the smaller pipe with the bolt to pull it into the bearing. heat the inner race of the crank bearing and freeze the crank(in a bag with oil) for a couple of hours, and it will slide in most of the way. then finish it off with the puller. the right side case will slide right over the crank. you could press in the crank too, but you need to stick a chisel or something wide enough between the crank halves to hold the true, but its kind of awkward. you shouldn't use a hammer though.

[2muchquad]

A puller is a good idea if you got it but i havent used it on my 426.when assembly the cases the crank gear will touch the inner race of the bearing,but dont be alarmed it will fit over it.Make sure you loctite the bearing retainers in the crankcases as they will back out and stop your motor.I speak from experience,use loctite and get a puch and dimple the retaining screws as well.I have used 2 or 3 big C clamps in the past and i would tighten each one little by little until the cases were together.if done right you shouldnt need to use the hammer even though it will be tempting to do so.