Posts
17
Joined
5/23/2022
Location
Little Rock, AR
US
Edited Date/Time
6/18/2022 3:31pm
05 YZ 250. Both chain rollers were gone off the bike and I didn't notice it. Anyways I was riding the bike and about 30 minutes in I got on the gas to come out of a corner and the bike locked up.
Initially thought it was the motor but I was happily surprised to see that it had eaten the chain slack and it got all caught up between the front counter sprocket and the swing arm on the bottom side. Had to take the shock and swing arm loose to get the chain out but it wasn't too bad. No visible damage to sprocket or chain just some scratches on swing arm.. Put new chain rollers on. Good to go.
Bike now has a bad knock while in gear. Idles and revs in neutral just fine. Once in gear it has a knock directly correlated with the RPMs. Sounds like a hammer hitting the case.
I'm fairly certain at this point I'll have to split the cases but I'm wondering if there's anything I can check that could possibly cause this without having to tear the motor completely apart?
Initially thought it was the motor but I was happily surprised to see that it had eaten the chain slack and it got all caught up between the front counter sprocket and the swing arm on the bottom side. Had to take the shock and swing arm loose to get the chain out but it wasn't too bad. No visible damage to sprocket or chain just some scratches on swing arm.. Put new chain rollers on. Good to go.
Bike now has a bad knock while in gear. Idles and revs in neutral just fine. Once in gear it has a knock directly correlated with the RPMs. Sounds like a hammer hitting the case.
I'm fairly certain at this point I'll have to split the cases but I'm wondering if there's anything I can check that could possibly cause this without having to tear the motor completely apart?
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Personally, if this were my bike and I had just bought it... I would usually start with a complete fresh motor top and bottom.
So into the motor we go. Is it imperative to use a case splitting tool or can it be done without one and preferably without scratching the shit out of the engine? Same with the flywheel puller and bearing/slide hammer tool. Is it all necessary? I don't have these tools and I'd need to order them.
-flywheel puller
-clutch hub holder pliers
-case splitter
To assemble correctly, I’d also get a crank puller. This pulls the left side case over the crank and pulls the cases together without damaging the crank
Rocky Mountain ATV offers these tools through their Tusk line and are affordably priced. If you don’t have these tools, there’s a good chance you will do damage to the motor and incur more cost than what the tools would cost. If you feel you’re in over your head, find a reputable mechanic to do the bottom end for you. If you feel you’re up to it, get an OEM shop manual and take it slow. Good luck!
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