Is this a job for the stealership?

[screamin kanji]

Well, I hate to say it but the stealership may have me by the cuhoneys. I was riding yesterday when I noticed my bike had a slight pause of power in 1st gear. I had it checked by stealership to see how? what? why? I was told by the mechanic after riding it "I believe the shift fork is bent". "Ok, well how much is that gonna cost me?" about $700.00(600.00 forlabor + $15.00 part). My jaw hit the floor. I asked the cause of this and wsas told "wheelies" or "standing on the shifter", but I do neither 1 of them. Too chicken-poop for wheelies, and not into replacing fork seals, and I never stand on my shifter. I bought the bike used. Musta been owned by a SQUID. Anyway, has anyone replaced the shift fork in theior baby? I am mechanically inclined(x-diesel mechanic), is this a job for the stealership?

 

[screamin kanji]

Oh, and I erased my only copy of the manual when I replaced my hard-drive last month, so I dont have a manual to check this myself.

 

[heykenny]

couple things... first, a shift fork is not a 15 dollar part, it's more like 80.. and second; bent shift forks don't cause transmission problems......... transmission problems cause bent shift forks.. what I mean is, you can be assured of finding gear damage in addition to the bad fork. Your looking at a minimum of 300 in parts.

 

[screamin kanji]

let me ask, it doesnt seem to jump/skip power every time. do you think its a shift fork?

 

[screamin kanji]

it really feels like chain is jumping or skipping a tooth. not really a power loss.

 

[ktw88q]

Check your tire pressure and chain adj...

 

[screamin kanji]

i checked tire press. and chain adjustment. mechanic checked adjustment of chain before he rode it. good there.

 

[twotonevert]

OK, not wanting to sound stupid, but just thinking out loud. You dont have a bunch of slack in your throttle cable do you? If so, it may jerk and seem irratic.

 

[heykenny]

Assuming it isn't a chain skipping.(I'm sure you've checked) The most likely cause is gear damage.. You see, shift forks don't do the work of holding a trans in any given gear. They are just the indexer. They just move the gear to the appropriate position so the dogs and slots can engage their undercutting. It's this undercutting on the trans gears that maintains the positive lock. When the dogs or slots have sustained enough damage,they no longer lock securely and will try to exit from each other. It's this movement of the gears apart from their chosen location that bends the fork.
Putting a new fork on a bad gear set will just cause the same scene to play itself out again the next time enough power is applied. To properly correct the issue usually requires the gear, the engagement gear, and the fork. A typical "bad gear" scenario usually requires all three parts. And a trans that has been used hard enough to ruin some gears usually has other damage. I don't mean to scare you or depress you,but, it sounds like time for a teardown and a proper inspection.

 

[screamin kanji]

OK, not wanting to sound stupid, but just thinking out loud. You dont have a bunch of slack in your throttle cable do you? If so, it may jerk and seem irratic.

throttle cable is good , I assure you., thanks

 

[screamin kanji]

heykenny, I am ready to ship you my tranny, you sound like you know what you are talking about. So where am I sending this? Sounds to me like you have hit the nail on the head, but let me ask this, If it were a bad-gear, wouldnt it do it all the time? in that gear? it only seems to do it under heavy throttle.

 

[screamin kanji]

 

[heykenny]

If it were a bad-gear, wouldnt it do it all the time? in that gear? it only seems to do it under heavy throttle.

A gear set that is worn but hasn't yet broken the engagement dogs exhibits this type of behavior.. the gear is being held in place by a now tortured and abused shift fork. As the torque increases,it overpowers the forks ability to hold it,and skips, flexing/bending/burning the fork as the fork tries desperately to keep the gear in place. When the torque load is light, the stubborn,stoic, under-appreciated shift fork is still there trying to hold it in gear, and may actually succeed for a time.

 

[screamin kanji]

heykenny, is this a job I can handle, or do I bite the bullet and give it to the stealership?

 

[Trachito]

have u checked the sprockets to make sure ur not missing any teeth? front and rear. that can cause a jolt and a rattle. also the cam chain tensioner can cause rattling and uneven power distribution. also, when i had an old RF600 zuki, when the clutch was going out, it would feel like the tranny skipped and i'd barely accelerate while the engine would rev high for a second or two. this didn't cause any rattling though.

 

[screamin kanji]

sprockets look ok, mechanic verified that. no rattling noise being heard. just a really quick dive and boom, right back up on power.

 

[heykenny]

heykenny, is this a job I can handle, or do I bite the bullet and give it to the stealership?

I'm sure I wouldn't be able to judge your abilities,since we've never met. It's not technically very difficult. With a factory manual and plenty of patience,any decent mechanic can do it. It's hella tedious though. Many bright guys have chosen to just have someone do it based on the "pain in the butt" factor. By the time a noob gets done checking and double-checking and self-doubting and staying up nights worrying about it being done right... well, you get the idea.

 

[screamin kanji]

thanks heykenny. I'll look at it as me doing my part to stimulate the economy.

 

[heykenny]

Best of luck to ya. Interview your shop people to get a good feel for their competence and don't forget to have them show you the affected items so you can see exactly the items we've been discussing. It'll be an interesting journey for you (inside the trans,not to the bank when you get the bill). The next time someone posts this issue, maybe you'll be the one able to help..

 

[screamin kanji]

I'll sure try to help anyone in need. If I can help anyone here, I will.