Motorcycle Transmission Problem

[bushpilot]

Zook-

I stand corrected, there are some that use springs on the shift forks...
and i dont know that particular bike/trans.

bmw & moto guzzi dont use springs on the selector forks...ill have to
refer to my service manuals on the other bikes we own.

 

[Zookie400]

i didnt catch that it was a 99, so i would have to assume he has a shifter pin/return spring. most other styles of transmissions were older and "experimental".

this bike isnt auto clutch is it?

 

[bushpilot]

im betting its worn dogs

meant to include some links...
how motorcycle transmissions work - Google Search

 

[JimmyDee]

im betting its worn dogs

I think you are correct. Found out what was wrong. The low gear mates with another gear, not sure which one, with elongated cogs (or as you called them, dogs) into matching holes in the other gear. What happens is both the cogs and matching holes round off and will drop out under heavy torque and then slam back in. Both gears have to be changed as well as the forks that slide the gear.
About $800-$1000. Engine has to be pulled and the crank case split which means taking apart the entire engine. Fairly common with high miles but 7500 miles is not a lot. The 1100 Yahama has this problem as a weakness also but it was never at this low of miles. Mechanic showed me a set of gears that he said would look just like mine. The dogs and mating holes were totally worn.
Jim
BTW, decided not to do it myself and thanks for the responces.

 

[bushpilot]

do i get a cold beer as my prize
so this is the diagnoses w/out even opening it ?

its not an easy job, but for 1000 bucks id be doing it
myself (course ive been inside motorcycle trannies before).

good winter project (you are in MI after all)...removing the
engine is the hardest part...and depending on the engine cracking
the cases might not be as bad a job as you think.

my problem w/ these "jobs" is they lead to upgrades...bore kits etc....
i mean "HEY" were in there...why not do it...

7k is NOT alot of miles, i agree. Ive got 43k on my bmw touring bike
and no other motorcycle of ours (w/ the exception of my wifes duc-monster) has
less than that...most have between 14 & 30k on 'em.

its a bit disappointing that kawi didnt build that tranny better than that....
are you the original owner ? it could have been a defective shifting fork but
USUALLY this type of wear is from "abuse" (hole shots ? burn outs ?)

perhaps kawi just used a poor quality part....although they are known
for GOOD strong systems...ive had no problems w/ my 99 zrx (which ive
done some internal work to).

 

[JimmyDee]

so this is the diagnoses w/out even opening it ?

Yes it is. I trust the guy and he has done many of them with exactly the same symptoms. I think he gave me a high price just to cover his hind side. What ever it is, it is. He's going to clean the carbs and a few other things while he is at it.
No, I am not the first owner but my son was. Rear tire had a lot of tread left when I changed it at 7200 miles so I don't think it was abused.
Now if we were talking about my last bike, Yamaha V-Max, that would be a different story. Went through a tire fast with that one.
Jim

 

[Zookie400]

while we are on this topic, i got a call from my brother who was up in main for a race (i couldnt go, have horse things to do sunday). he called me to inform me that he BLEW the back half of the cases apart during practice, and its "not so driveable" at the moment. so they are packed up and headed back...didnt even make it to the qualifier race.
from what he described, the sprocket shaft has ripped back blowing apart the cases. he said it still shifts, the engine runs although it is now out of oil, but he cant get neutral and the output shaft/sprocket arent at the proper angle.
so i will be splitting some cases monday night to assess damages. im hoping the cases just fatigued and let go allowing the output shaft to rip back under the force from landing a jump while on the throttle, but with our luck the trans will come out like steal mulch.
the crappy part of all this is that he has a deposit on the quad, because he moves up into the big boy quads next year. i hope they still want to buy it after we rebuild it!
stay tuned, ill post pics tomorrow (assuming it looks as nasty as it sounds)

 

[bushpilot]

cant wait to see photos of THAT carnage !
cant say ive ever seen cases come part...maybe the
output shaft bearing let go ?

almost sounds like the chain broke and knocked a HOLE
in the case (of which ive seen WAY too often)

 

[kbud14]

When I read this, I thought worn dogs, same as bush called. If you replace a gear because of worn dogs, it is good to replace the gear that it slides into. You dont want to have to split the cases again.

 

[Zookie400]

ok sorry for the delay but here are some not high quality pics of the damage. im not sure what happened, there are broken bolts on the rear sprocket so one theory is a rock got caught between the chain and sprocket and ripped the output shaft straight back out of the cases. there is no internal damage other than blown apart cases......????