Can anyone help?

[Pancakes]

Hey guys, my GN's starter has started engaging whenever it feels like it, not when I tell it to. Very bad (locked up once 'round a corner and once while I's splitting). I don't want to get hurt or break the bike, especially as the car is in pieces at the moment. Does anyone know if I can take the starter cover off without oil coming out? Is anyone game enough to take a look (it still rides so I can take it places, my hand just hovers over the clutch). I think I might just need to adjust whatever it is that keeps the starter tucked away normally but don't want to crap it up. Any ideas please PM me. I'll check this regularly too and update it if I get it sorted. Thanks KB'ers!

[erik]

It must have a different sort of starter engagement mechanism to what my bike has if it's making the back wheel lock up. My zeal has a sort of one-way clutch.

Is the starter engaging because power is going to it, or is it just engaging some other way?
If it was engaging due to power going to it, the starter switch would be the most likely culprit, I'd guess.

I don't know much about GN's, but this sounds interesting.

[Ixion]

No, a sticky starter switch won't do any harm, except maybe burn out the starter motor. Makes a noise , so you'd know it . Ratty's sticks occasionally.

The engine, when running will always be going faster than the starter would spin it, so the ramp clutch should not engage. Sounds like the clutch is locking up , and trying to spin the starter at a gazillion revs per minute. Still wouldn't have thought that would have locked a wheel, but I guess those itty bitty cylinders would lock real easy.

Doubt that the ramp clutch is adjustable. Prolly blow the starter rotor if it happens too often. Could be jolly expensive.

[FROSTY:Me]

Gimme a yell dude- 8322557
it wont be the starter MOTOR -but the rod the starter clutch rides on could be knackered I guess -there aint any way that anything less than metal jammed on metal will cause the motor to stop like that on the gnu
Imental images of gnu innards are dancing before my eyes
--Hey heres an idea --How about we toss the motor from a FZR250 in the gnu --I happen to have a very much alive one sitting here

[Pancakes]

Yeah, it's always made a loudish rattling noise and when I bought it Sarge (got it from Colemans) said he thought it was the starter. (I bought it cheap, as is where is so I don't hold the shop responsible in any way). The noise sounds just like the starter engaging at REAL high rev's (think 40 then 70k's). The first time I was laying it over around the greasyiest intersection in my area, it's slippery enough that I can spin it up at about 4 grand in second, no clutch or anything and thats saying something cos it's no grunter. The next time, wet cats-eye's while splitting. I'm surprised I didn't go down the first time. I'm about to go and pull the cover off so if anyone knows what the mechanisim should look like (weights to engage it when the starter? A splined thing?) I guess I'll find out in a minute. I'm going to check back after having a poke around, see if you smarty-pants'es know anything. Cheers for the replies!

edit. Frosty, just saw that. Thanks.

another edit. Your phones engaged, I'll try again soon.

[Pancakes]

Frosty, your mental image was spot on. The starter goes into the left side cover and I spent a bit listening to it which just confused me. Spent last night taking the head off the car so I'm not messing with the bike tonight. I'll try not to make it angry and if you do have a spare moment I could come 'round to yours and we could stare at it and go "ummm" together? (and maybe even find out whats wrong). Oh well, it's all tucked up in the garge now and I'm off to bed. (soon, after I check out some of the other posts, just no-one tell my wife, she says I have issues with "bike porn").

[Ixion]

This is a GZ250, but the principle is the same on almost all small bike starters.

There are three rollers, They ride on inclined ramps. When the carrier spins one way, the rollers ride up the ramp and jam, which imparts the rotation force to teh engine. Spinning the other way , the rollers run back down the ramps to the bottom (where they spin freely).

Something is jamming your starter clutch so it is "clutching" both ways.

[Pancakes]

Your right and it sucks. Can this act like a generator and feed a current (too much maybe if it happens at 70 in 5th?) back into the system and toast bits? I'm guessing the starter button (that I don't press while doing 70) being normally open would stop that happening but if what we all seem to think it is is what it is, is it going to do something nasty at that speed? (He waits for Hitcher after that sentence).

[Ixion]

Your right and it sucks. Can this act like a generator and feed a current (too much maybe if it happens at 70 in 5th?) back into the system and toast bits? I'm guessing the starter button (that I don't press while doing 70) being normally open would stop that happening but if what we all seem to think it is is what it is, is it going to do something nasty at that speed? (He waits for Hitcher after that sentence).

Well, the biggest problem is that normally the starter is geared down a lot so that it has enough torque to turn the engine. So a few thousand rpm on the starter rotor beomes a few hundred rpm at the engine, but that's enough to start the engine. BUT - if that clutch is jammed , and your engine is doing say 5000 rpm, that gearing goes the other way - 5000 rpm at the bike engine becomes 50000 rpm at the starter rotor. Doesn't take too much of that for something to go bang
I think mechanical damage is more likely than electrical.

[Pancakes]

Give that man a dollar! Ten points for choosing "C: Mecanical failure" Ixion! It happened again!! Now when I press the starter button it sounds like a drill turning in a jar of bearings. Good and bad I suppose, now there's no mechanical connection, my skid issue should be sorted but who thought taking a kick start off a GN was helping anybody?! Frosty, I might take you up on that offer of the now clear garge floor? Maybe PM me your address if you have time sometime? Any other hints or spare starter motors/clutches from anybody happily accepted. Thanks for the hints etc so far guys.

edit. No-one panic, I'm still riding! It's just run and leap, putt putt putt.