Jumping out of 2nd gear

[Gunny]

My scooter was jumping out of sencond gear every time i hit the powerband now it just kangaroos in 2nd, it's fine in all other gears but it does have a tendency to jump into gesr if you rev it's tits off standing idol , thing has a mind of it's own.
I've change gear selectors to try and cure it but nothing seems to be working....
Anyone got an idea what it could be ??

cheers

[H,POOL GADGE]

Cruciforms gone!!! no cure apart from split the engine,But! on the plus side, you can replace it with engine in the frame, easy job gadge!!!

[Gunny]

Na the cruciform is spanking new so can't be that..

[H,POOL GADGE]

okay, ye second gear cogs gotta chip or rounded or generally worn were the cruciform catches the cog or maybe you need to check the shim clearance on the cog stack

[Gunny]

Ive had it stripped and rebuilt loads of times checked everything over and over seems smack on to me.
The engine is tuned to the max 220cc watercooled fuel pump 30m carb everyhing. built by sean and was fine till it shed teeth on the xmas tree in 3rd but since i've put it back together it jumps like f@@k in 2nd . All other gears are fine. just seems strange and i can't work out why.

It was the jumping into gear when i rev'd it had that f@@ked me off !! would or could to much vibration be able to do that to the scoot ??

[wack 63]

My tuppense worth, 2nd gear in wrong way,cruciform shaft loose,cruciform damaged,selector box worn or wrong one fitted,selector box spring broken,gear shimming.

[Daz Kane]

My tuppense worth, 2nd gear in wrong way,cruciform shaft loose,cruciform damaged,selector box worn or wrong one fitted,selector box spring broken,gear shimming.

yeah wot he said that'll just about cover it :fb:

[fraserp200e]

My tuppense worth, 2nd gear in wrong way,cruciform shaft loose,cruciform damaged,selector box worn or wrong one fitted,selector box spring broken,gear shimming.

yeah wot he said that'll just about cover it :fb:

I would go for the gear in the wrong way if it was running fine before you stripped it, easy to flip the gear over when it's all in bits. Any time I've had a cruciform go, it's always 4th and 3rd that have started jumping first.

Remember to post up when you find the snag.

[Gunny]

Stripped the engine down to find 3 teeth missing of 4th gear on xmas tree, found 2 in the oil and loads of bits of the other one mashed into the casings ground to dust nearly. so new xmas tree, think i'll try the SIP uprated number along with lengthing the gear ratio as it revs out with P2 4th...
But need to weld a tiny hairline fracture on the casings just next to the flywheel..is this a common place for the engine to fracture ?

[wack 63]

Strange that as usually when the teeth shear there will be no drive.