Jerky bike

[ducatilover]

Are you talking about the pipe to the carb?
It needs to sit on the battery box, or airbox in still air. Otherwise you'll make the poor girl run pig rich when it gets pressurised

[duckonin]

If he sees Katman he has some brains . Yep c the kat.

[bosslady]

If he sees Katman he has some brains . Yep c the kat.

She... heh

[FJRider]

If he sees Katman he has some brains . Yep c the kat.

Grashopper is a SHE ...

[clonak]

Couple of things I noted from my GZ, same engine, different carb. When I purchased the bike it was quite jerky, and got worse and worse, thinking the chain was loose went to tighen it. Half the chain was tight, half the chain was loose, and there for naffed. replaced it, and it was fine. Untill the intake manifold (from the carb to the cylander head) apparently cracked (so I have been told by the mechanic that was to lazy to take it off and replace it.....) causing some problems, back firing and some jerky-ness.

Did you not just have an electrical problem recently as well ? Maybe the battery is not fully charged, the charging unit isnt the best in these smalls engines, so maybe cant handle with a half drained battery. I noticed a mild difference when I put a new battery in the GZ. Also run some carb cleaner through the fuel. On a GZ forum I am on, its the number one diagnoses and usualy fixes most of the problems.

[Grashopper]

Are you talking about the pipe to the carb?
It needs to sit on the battery box, or airbox in still air. Otherwise you'll make the poor girl run pig rich when it gets pressurised

Good thought. I'm pretty sure it was the little battery overflow pipe. Didn't know there were more of those open pipes around though. Better check tomorrow.

[Grashopper]

@clonak
The battery thing makes sense. Will check that and keep the other things in mind. Carb cleaner is probably a good idea anyway. Will look that up. Many thanks

[ducatilover]

The battery box vent will have no effect whatsoever on the performance

The manifold could be split, unlikely on one that new though. There is a rubber o-ring on the manifold-to-head surface that can shit out... a cheeky bit of sealant will sort it

[skippa1]

C When I purchased the bike it was quite jerky, and got worse and worse, thinking the chain was loose went to tighen it. Half the chain was tight, half the chain was loose, and there for naffed. replaced it, and it was fine. .

aaaayyyyyeeee????? dont tell me....the top of the chain was tight and the bottom was loose?

[clonak]

aaaayyyyyeeee????? dont tell me....the top of the chain was tight and the bottom was loose?

No. I tighened the chain, which must have been at the loose half, and when I tried to move the wheel, it got alot tighter, so I loosened it off, then moved the wheel and it was waay to loose, done this a coulpe of times, and realised what was happening. Half had stretched to much, the other half had not stretched. Dont ask me how it works, because I was confused as hell as well. Was the first chain i had done on a motorbike.

[Grashopper]

Thanks again to Katman for sorting out my bike. He took it for a test ride and didn't actually notice anything wrong with it. Quite a relief, cause I was a wee bit worried. He also checked the chain which seems to be ok and adjusted the fuel/air mix to have run a bit richer. Seemed to have helped but I haven't managed to get on the bike for too long yet today.

[bosslady]

Thanks again to Katman for sorting out my bike. He took it for a test ride and didn't actually notice anything wrong with it. Quite a relief, cause I was a wee bit worried. He also checked the chain which seems to be ok and adjusted the fuel/air mix to have run a bit richer. Seemed to have helped but I haven't managed to get on the bike for too long yet today.

+1 to Katman, good on ya mate.

Grashopper, you may have worried about what appeared to be nothing but the relief in knowing it's ok is so worth it esp to a newbies confidence.

[craigdek]

No. I tighened the chain, which must have been at the loose half, and when I tried to move the wheel, it got alot tighter, so I loosened it off, then moved the wheel and it was waay to loose, done this a coulpe of times, and realised what was happening. Half had stretched to much, the other half had not stretched. Dont ask me how it works, because I was confused as hell as well. Was the first chain i had done on a motorbike.

Sounds like a Chain with seized links. Got dry and was standing so gravity stretched it. Had that on an old off road bike. Threw away that chain. Part of it was good for wrapping around your fist to smash taxi windows when they pulled a 9mm in SA lol.

[Grashopper]

Here an update on the jerky bike issue. We checked the frontsprocket the other day. Turns out it had two teeth less than GNs usually have. Upgraded to one tooth more and voila suddenly I have a much smoother running bike which doesn't feel like it's dying at 100 kmh anymore.

[FJRider]

Here an update on the jerky bike issue. We checked the frontsprocket the other day. Turns out it had two teeth less than GNs usually have. Upgraded to one tooth more and voila suddenly I have a much smoother running bike which doesn't feel like it's dying at 100 kmh anymore.

That would effectively gear the bike up. (ie: Go faster) ... Two extra teeth on the front cog is quite a bit.