Scooter bogging down on take off

[Spazman727]

Hi, a friend of mine has a scooter that, when taking off at the lights or whatever, has started to bog down a bit, not so far as to stall but just drops revs. He said that it seems to run fine once up to speed but the engine seems to struggle a bit when he first takes off.
Im not too sure of the make, model, year or kms, but can get these if it would help.

Any ideas?

Thanks

[JimO]

handbrake still on?

[FJRider]

The one's with the yellow power band do that ...

[p.dath]

Too many pies?

[p.dath]

Any ideas?


Could be a million things. How long since it was last serviced? Might just need a bit of love.

[Akzle]

centrifugal clutch = shat throwout springs.

[caspernz]

Apart from Akzle making sense...the things that cracked me up were: Scooter...and a friend of mine...really?

[SS90]

centrifugal clutch = shat throwout springs.
Unlikely.

The more common fault is the variator rollers (the plastic rollers between the front pulley and belt)

These are a service item, and quite often inn NZ are ignored. if they get a flat spot (normal use this is a part that only lasts 5,000 or so miles, less in extreme stop start situations, tye scooter will suffer tye exact symptom you describe.

Also, make sure the roller weights are tye correct weight, ,if they are too light, the symptom is the same.

[DanielM8]

Don't want to look like the fool around here by knowing scooters but since I can't afford a bike and swear that's the only reason you'll find me on a scooter... these scooters almost all use carbs, not EFI, so it's either a blocked carb, or it's the mixture. water blocks these carbs pretty easily if he has a pod filter.. and they suck in dirt in any case. Open the carb and clean it is the best bet, and if it still does it adjust the mixture with the mixture screw located on the side of the carb... don't mistake it for the drainage screw by the pipe.

[DangerMice]

I think SS90 is on the money. Whenever I start bogging a bit I know's time for new rollers and drive belt (every 5-6000km or so, but sliders last a bit longer). Good as new afterwards. When were these last replaced?

[Spazman727]

Not sure when they were last replaced as it is my friends scooter, I'll ask him next time I see him, but it's probably been a good while since anything much was done,
Thanks for all the replies.

[sgtp]

When its on the center stand, do you notice the same behavior when giving throttle? ie: does revs drop then gradually speed up when the throttle is wide open? If so, this might just mean the A/F ratio is too lean. I'd clean the filter and tune the carb (maybe replace the spark plug while you're at it before opening things up to check the rollers. My rollers are at 11,000km with only slight flat spots and I don't have this problem (but have delt with many A/f issues :rolleyes:) but I do plan on replacing the rollers when a new belt goes on soon.