revs problem

[roadrunnerian]

hi i have a gp 200 with a stage 4 barrell and asso piston cut off by a so called tuner. i have encounted a problem sometimes when i kick it up the scooter will not rev it justs ticks over no matter how much you open the throttle this will go on for a few minutes then all of sudden it will start to rev. it has happened when i had both of mine 22mm carb and 28 mm carb and i have fitted a new fast flow petrol cab and i have cleaned out the carb and filters this morning and i went out for a run stopped at the pub with the lads came out and no revs any ideas please thanks

[monkey boy]

Hi
You sure the handlebar grip is not slipping on the sleeve?

[pete maisey]

Possibly an electronic ignition fault (Black pickup) or blocked tailpipe.
I've had both of these happen to me.

Pete

[chris2470]

Next time this happens , remove the air filter hose form the carb mouth and see if this helps. It could be unburnt fuel getting spit back against it, especially if the inlet timing has been increased with a cut piston.

[roadrunnerian]

thanks for the replies guys, chris i have noticed that there is alot of unused fuel and oil in my filter hose.
monkey boy i will check if the slide is going up and down next time it does it.pete i am in the process of changing my exhaust and i will check my wiring thanks again if anyone else has any ideas please let me know thanks

[vince]

It could be caused if to much piston has been cut away giving an excessive inlet timing. But once revved up I assume its ok?

[J1MS]

I think it might be a combination of two things maybe three.

1... A largish inlet timing combined with, 2... poor low down carburation.

Plus possibly 3... if it's an SIL electronic a weak spark at low revs. Some stators I've tested will not produce a reliable spark till around 800 rpm or more..

But it's probably somthing else, as I'm just guessing.

Hope you sort it out soon.

[sean brady scooters]

I would try the 1mm drain hole in the very bottom of hose on this.....

[bazman]

I would try the 1mm drain hole in the very bottom of hose on this.....

What he said.......

[squeakmillward]

I would try the 1mm drain hole in the very bottom of hose on this.....

What he said.......

what do you mean?