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bobsmith
31st July 2006, 11:07
Hi all...

So this is a problem I've noticed time to time and I think it's getting more frequent...

Sometimes when I quickly shift up from first into second under acceleration, the bikes accelerates for a while but than the gear "lets go" and it goes into neutral, which proceeds to make me sound like a complete dickhead revving the shit out of the bike while not accelerating, usually, if push it up to second again and gently accelerate out, there's no problem and it doesn't seem to happen when I'm not accelerating hard either.

What do you think the problem is? the gearbox? clutch???

Any help will be appreciated.

Thanks!

R6_kid
31st July 2006, 11:15
sounds like you have a similar problem too me, cept mine only happens when i do it when wheelie-ing.

from what i've been told its the gear shift forks not engaging properly.

How many km's has your bike done?

bobsmith
31st July 2006, 11:15
35000 km or so....

SimJen
31st July 2006, 11:18
May just be the gear shift lever could do with adjustment so it suits your foot.
It might be that the shift forks are getting worn, but a good solid gearshift might stop it jumping out. I used to get it with the odd lazy shift.

F5 Dave
31st July 2006, 17:52
The change from 1-2nd is the longest physically as the shift star has to travel over the neutral position. Esp if the lever is rubbing against something. Sometimes a weak detent spring (which rides the wheel on the star) will exacerbate the problem.
Worse there is the biggest torque jump in this change.

Now this may sound silly but if your gear lever is at a funny angle like fairly high you may simply just not be regularly lifting your foot high enough or it may rub against the case slightly to prevent full travel. Make sure the lever bites onto the spline tight.

It can help as a technique to load the lever with your foot, not touch the clutch & cut the throttle; once the load is removed it will change.


But if jumping out & getting worse then it’s not good. Most likely wear on the dogs. A stiffer detent spring may help if not too late. If the change doesn't pull the star fuly around it can jump back out.


If there is damage to the gears then the places to look are the engaging fingers that mesh into the slots of the gears. Little bit rounded or angled? The problem is this damage will tend to push the gear back out rather than engaging.

These can be undercut so the gears pull together, however care is required to avoid pulling them so they move too close. Also the shift forks may be bent so they don’t mesh far enough in. Talk to a decent tuner if you have them apart.

bobsmith
31st July 2006, 21:39
Thanks a lot for the info.

I don't know if I'm making sense but I don't think it's ever happened when I do a clutchless shift up (like you described with loading the gear and cutting the throttle, ... ish) but it only happens when I change gear using the clutch. If it helps, sometimes I shift up from second to third just to release the clutch and realise that I haven't... so perhaps my gear lever is too high for me and I'm not pushing it up enough???

Wasp
31st July 2006, 23:23
So how about this one then:

once or twice now when changing up from 4th to 5th gear engages then lets go completely as if in neautral. i blame incomplete shifting due to a raised gear lever but im not sure....

Gremlin
5th August 2006, 01:48
When was your last oil change?

Had that on my old zzr250, and my zx7r, and both times, it was old oil. Changing it made the shifting much better.

Flyingpony
7th August 2006, 09:14
Assuming there's no fault in the gearbox:

Change the oil becuase, it's old, not enough or not fully synth - yes that makes a difference - ligher, smoother & reduces grinding.

Adjust gear lever so it's positioned lower, it's probably too high right now and therefore you're not properly engaging the next gear. Ride with boots and then office shoes, you'll know what I mean.

Your gear shifts could be too quick for the gearbox, slow down a tad.

> .. which proceeds to make me sound like a complete dickhead revving the shit out of the bike while not accelerating ..
:killingme You need to be quicker at closing the throttle, it shouldn't blip by more than a thou or two when jumping out of gear under load.

bobsmith
7th August 2006, 09:17
yes... I will get around to lowering the gear lever one of these days (I've been pretty damn lazy lately...) I was thinking I never had such problem on the fxr but than the gear lever was much lower on the fxr so I'm thinking that maybe the problem...