need some urgent info

[Tack]

I need to know on a 1991 GPX250, if you can put it into second gear when the engine isn't running?

thanks for your help.

Edit: Actually need to know if you can select all the gears when the engine isn't running...that is....select first then second then third etc running up and down through the gears without to much problem??

[JamesLaugesen]

Yes, you might need to rock the bike back and foward a bit and play with the clutch, so the gears mesh together for the change.
Wont do any harm though so don't worry... just remember what gear you left it in .

[Tack]

thanks James for replying however its real important that i know a GPX250 will definately change gears with a little rocking etc to get the gear....I know that in general most bikes will but just need to be sure that a GPX will.

thanks.

[dave#3]

Tack,

To add to what James has said. The positive neutral finder stops you moving above neutral (ie only 1st or neutral) when you are not moving - to overcome this put the bike up on the centre stand and roll the rear wheel slowly (with the clutch in) - you could also do this rolling the bike around but on the stand is probably easier.

Once the rear wheel is moving a little you can select 2nd gear - from there the positive neutral finder has no effect so you can move through 2-6 without any additional work. Until the rear wheel is moving you will *not* be able to select 2nd.

If you return to neutral or first you will need to repeat the above.

Hope this helps.

[Ment]

well i can say from very embarrasing personal experiance, that a zx7r wont due to the positive neutral finder.

im not sure if the GPX has one but if you can change into second while moving and not whilst stationary, im guessing it has one.

hope that helps.

[Tack]

thanks for your replies guys...the situation is basically this:

I have had to strip the engine and replace a bearing on the output shaft that disintegrated (literally). I have replaced the bearing and as part of my reassembly procedure I decided to check that the gearbox will run through the gears (just to make sure that everything works so I don't have to pull it apart again).

Bottom line is: it selects 1st gear then it won't select second ( tried everything to get it into 2nd...spinning the shaft...rocking it) The positive neutral finder has not been fitted.....I then found that moving the bearing on the output shaft slightly allowed the fork pin to move about 1mm in the selector drum groove which then allowed selection of 2nd gear(because the dog for 1st gear has three small balls to restrict its travel which then stops the fork from moving in its guide which stops the selector drum from rotating...). However after moving the bearing slightly I could select second and third...but not 4th....if you then moved the shaft slightly back the opposite way to its original position it would then select 4th 5th and 6th gears.

I looked at forks to see if they were bent....which they are not.... so I was stumped...i can't see a reason for the thing not to change into second gear except for the selector drum not being able to rotate due to the restriction of the three little balls in the dog drive...Thats why I decided to just ask a simple question to see if everyone else with a GPX250 can change gear ...just to double check!!

It appears if the shaft is in the original position that the only gear I can't select is 2nd gear so I thought there might be something distinct to this bike that doesn't allow a change to second without it running or moving or something weird like that. I thought maybe it relied on centrifical force to force the balls out and allow the dog to move or maybe it worked through oil pressure or maybe the GPX is the only bike on the market that has artifical intelligence which prevents 2nd gear from engaging unless it knows you really do need to be in 2nd gear

[MickLC]

I'm a bit confused mate, you've said the positive neutral finder isn't fitted, then go on to talk about the three little ball bearings in the dog...they are the positive neutral finder!

The output shaft needs to be spinning enough for the centrifugal force to push them all out which then allows the dogs to move enough to select 2nd. When you are stationary at least one of them will slip down and lock the dog so you can't get past neutral.

Make sure when you reassemble that you don't put any grease or anything on them to hold them in place, otherwise you'll never get out of neutral!

[Tack]

yep ok, bit of confusion on my part as I thought people were referring to the neutral positioning bolt. The three balls are part of the positive neutral finder and won't allow you to get second unless the thing is moving. Can you get second gear when the engine is off....the answer is, I'm told by Brighton Kawasaki and correctly pointed out by a few people here, NO!

Thanks for everyone's input.

[99coconuts]

thats interesting, cos my GFs old bike could maybe there was something wrong with it? hangon, i just answered my own question didn't i

how about the 4-5 thing there tack, did you work that out aswell?

[Tack]

Well by moving the gear set over slightly to allow 2nd gear to operate it allowed all the gears to work except the ones that were affected by the move....so moving the gears back to the original position that allowed them to work as well.....so bottom line is that you can't test a GPX box on the bench for gears....you just gotta have faith! Thats why I have a sign on the ceiling of my workshop that says "GOD". At moments like these I look up at it and with arms spread I say....."Gawd help me!!"

[Jonno]

Very simple, just pull up in 2nd and stop the bike then all will become available