Quote: Originally Posted by Crazyotto
He just bought this machine for what we thought was a good deal but after we went 5 miles the bottom rod bearing blew apart. It was hell getting this thing as i did a rookie move and didn't strap my ramps to the truck and smashed my tailgate. When we got home we checked the valves and fluids and preeped for a trail ride. Not even 5 miles in it started knocking real loud. We shut it off and towed it home. After tearing into it we found the bottom rod bearing destroyed.
I think the guy knew it was going and didn't say anything about it.
This good deal is slowly turning into a big rip off if i can't find a aftermarket rod kit.
In the past I have repaired a two-stroke race bike for my son when this same thing happened to the lower connecting rod. It was an old Italijet race bike- no replacement crank kit available. Pressed the pin out and it was destroyed along with the bearing. Found a crank pin rebuild kit from a Yamaha YZ 80 and it had the same OD, but it was slightly longer. Had to shorten it to fit my application. Went to my bearing supply shop and matched up the "old" needle/rollers bearings to new ones. Pressed the crank pin back together, trued it up with v-blocks and dial indicator to check the throws for concentric and parallel and the bike is still running today. I know the owner.
I'm not sure what kind of bearing is in the Cat, I'm not sure what the crankpin is made of but if you can find a "kit" for say like another brand ( Suzuki, Yamaha, Honda, Kawasaki) with a crankpin the same OD that might just need shortened and you have access to the right tools-Press, lathe, mics, v-blocks etc,etc. you might be able to fix yourself. But then you still need to find a rod, because 90% chance it's hammered too......like I said Cat doesn't offer just the rod for the 550.
It is possible. Not for the beginner, and if you have never done one, or anything like this, I wouldn't recommend it.
Buy the crankshaft assembly and rod....thats your only other option other than if you can find a company that specializes in crankshaft rebuiding for motorcycles and ATV's. I would call Wiseco and LA Sleeve to see who they use.