another issue with my rebuild!

I have the case split and cannot get the left case side off of my crankshaft. For some reason the cam chain gear on the crank won't let the main bearing slide over it, their is a little wear on the gear but not sure what to do now? How much wear on that gear is to much and should be replaced?

Try to identify the tooth or teeth that is/are too tall and buzz the burr or whatever off it with a file.  If the gear is worn that badly, you're probably going to need at least that half of the crank. 

that's what I was guessing to do but figured I better ask. To tell if the gear is bad will their be slop when you put the cam chain around it?

I've also been planning on taking the case halves to work and put them in a solvent tank with mineral spirits. That won't hurt anything will it? Still got bearings in just figured I'd assembly lube them up when it goes back together.

Cleaning them in a solvent tank is fine, but be sure you thoroughly wash through the oil passages with clean solvent.  Also verify that the bearings are washed clean so the rotate freely and don't have a gritty feel when dry.  Best practice is to replace the whole set while you're there, but that adds up.  Careful inspection and your best guess is called for.  Be critical and selective.  New mains, new balancer shaft bearings, and the left side main shaft bearing (yes, the one in the blind hole) are on the top of the "don't reuse unless they're near perfect" list.

alright thanks! My uncle tried to rebuild the motor for me last winter so I already replace a bunch of bearings and have less the 2 hrs since then. I tore it back down because he didn't fix the transmission issue I was having ( drops out of 5th ). The bearings feel smooth, but don't really wanna tear the motor down again for awhile.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By faizakhtar125
      Hey guys I just bought a bike last night. So the seller said the bike will turn on but then die. We didn't try it because it was really late at night and it was raining (seat was wet). But he said if you bump start it, it will turn on and ride. So what do you think the problem is? I just want to make sure it runs... I probably won't be able to bump start it till Saturday (rain)... It's a four stroke, and I know absolutely nothing about them. Thanks.
    • By dpenn1
      I could use some feedback, My son is getting into off road riding so I have starting getting back into it as well.  We mostly do trail riding but did some MX track riding last year and he loved it andso did I.  I have a 2003 TTR 225, it's nice that it has an electric start but the suspension is too soft and it doesn't have enough power for my liking.  When I was riding the MX track I was having issues bottoming out on the larger jumps.  I want to change to a more off-road capable bike.   I won't ride it much and don't want to spend a lot of money, I think I prefer a 2 stroke, when I was younger, in 1990, I raced an 89 RM250 and loved it.  I am looking at a 96 RMX 250  and a 98 YZ400F, both bikes look to be in good condition and around a thousand dollars.  I like the RMX because I think kicking a 2 stroke 250 should be easier than a 4 stroke 400 and the simplicity of the 2 stroke engine.  The 400 sounds good because of the low end torque I assume it has but the cost of rebuilding the 4 stroke if needed worries me and I have heard they are hard to start. Should the RMX be decent for an occasional trip to an MX park?  Any thoughts on these two bikes? 
    • By yz480doinwork
      Brand new, still in the packaging Lexx end cap fits the stock muffler of 2006 & 2007 YZ450f and 06-13 YZ250f. Comes with a forest service approved spark arrestor and two different size tips. Don't spend hundreds of dollars on a slip on, this tip can be quiet and forest legal or loud and make power! Also a note for WR450 guys: get this tip and find a used 06/07 YZ muffler, fits directly on 09-15 WR450. $80 shipped free to the lower 48. PM, call or text 406-223-8789
    • By Woody Oakson
      So I have a 2008 yz450f and I would like to add some LED lights to it to make it street legal. Mainly just a headlight and a tail light and turn signals if I need to (which where I live hand signals work).
      So where I need help is getting power from the stator to a battery. Wiring from a battery to anything else I got and understand and don't need help with (but recommendations are welcome). So my questions are.
      What type of power is coming from the stator. AC or DC? Will I need a regulator or rectifier? How do I wire something from the stator to charge a battery? What would that wiring look like? Would this stator work? Anything else I should know? Any help would be appreciated. Thank you.