Hey all, I was wondering if anyone had some insight to a problem I discovered over the weekend.
After a hard day of riding, I noticed my 1990 LT250r was vibrating intermittently pretty badly. I had encountered this problem before, and I recognized it as a sheared woodruff key on the counterbalancer shaft. It's happened about twice since I put the bike back together-- do anyone have any idea why?
I'm suspecting that it's because I'm not torquing the nut that holds the gear on the shaft down enough. Back when I first put the bike together, I tried the penny trick to tighten the the nut. It worked so-so, but like an idiot I tried it with a washer to achieve proper torque and broke a tooth off the gear.
Is there anything else I'm missing or should be checking? Like I said before, this is the second time this has happened in as many rides and any leads would be appreciated.
As in penny between the gears?? I wouldnt do it that way man.. Theres a tool thats 20$ by motion pro that you can get or even make your own setup.. Just something to put into those two holes to hold the fly wheel.. I honestly think youve figured out the issue now just fix it correctly
I went through a similar issue on my 500. My key wasn't sheared though, whoever put the tranny together before I purchased it had the timing of the counterbalancer wrong. Derrick let me use a tool he made. It's a metal shaft with two bolts welded onto it that fit into the holes on the flywheel. It worked like a charm to hold the crank.
I also tried the penny trick along with having my dad holding onto the gear itself with massive channel works and that still didn't work.
Air Impact works great for on & off.
cheap 250-350 ft-lb impact wrench and red thread lock. do not tight the nut too much.
it is best to use torq wrench. A wooden 2x2 work good to jam the gear . Clean the nut and bolt threads with brake cleaner then apply
enough thread lock ! everything is written in the manual....
I feel like a good 80% of threads in this forum would not exist if dumbasses (like me) would just READ THE DAMN MANUAL!
Thread lock, impact wrench. The missing ingredients. Got it.
Nahh dude the manual should say to ise the correct tool to hold the flywheel in place. Not an impact wrench but it works
But we're not talking about the flywheel here. We're talking about the counterbalancer. You have to take the clutch basket off to get to it, so holding the flywheel in place wouldn't help much. I have the holder I think you're referring to. I was thinking I could use it to hold the gear itself (although the tines might be too thick for that gear) whilst torquing it down to the correct ft/lbs.
Ahh yepp i guess i read over that my bad dude!! You are right though with that tool it can also grab hold of the teeth of the gear.. Maybe could grind them down a tad bit more so they fit snuggly and tighter thwn could get a good torque
I think you've already addressed the cause of this issue... Just thought I'd add my $.02. Never had an issue spinning counter keys, but I have spun a few flywheel keys on highly mod/high rev. engines. I've found that making keys from larger size key stock, removing just enough material for a very tight keyway fit, virtually eliminated anymore spun keys.
ive had a key shearing problem before I ended up tig welding the gear to the balance weight