Engine stutter and power loss

Can somebody give me some advice for my lui 50cl. The problem i have is when the engine is reving high and approching top speed in each gear, it begins to stutter and looses power. I have serviced and cleaned the carb and the scooter idles very well, the scooter starts fine and runs very nicely.
If somebody could give me some ideas to try it would be appreciated.

Cheers David

Sounds electrical to me, unless your main jet is blocked. I'd try the easy bits first, new plug and cap plus H.T lead then going further onto the points and lastly your stator coil's and wiring from them . Welcome along too

...airfilter blocked,main jet/atomiser blocked,fuel tap/filters blocked,poorspark-fit champion n3/4 20 thou gap,ht cap wire,coil,point/condenser clean /re-gap/ change,poor flywheel magnetism,too much oil mix,crank seals,air leak,duff fuel,worn cylinder---if its not one of these then i dunno ?...old age...lambretta...oh what a joy !

..at idle does it die when you turn the lights on...?

any backfire ?
could be points bounce, as others have stated, i'd go for easy options first, new plu, ht lead, plug cap, check coil earth.

thanks for the suggestions........ seems i will have a busy weekend, i adjusted the points recently so this would be a good thing to double check first, i also used a different oil to mix in the fuel and it is smoking more than normal so maybe this is affecting things.
the engine continues to idle normally when i turn on the lights.
i put in a larger main jet aswell so maybe i should take this back to standard for now.

Cheers Dave

daz.h wrote:any backfire ?
could be points bounce, as others have stated, i'd go for easy options first, new plu, ht lead, plug cap, check coil earth.

no there is no backfire, why would you get point bouce? is it because the points are too close or that they are worn out?

I thought points bouncing was usually down to a tuned higher reving motor that needed a 12v electric conversion. I suppose the right timing is the common link between the 2

I've had a couple of scooters over the last few years that had symptoms similar to this. One had a slight leak at the head, the other worn rings. Both started and ran well up to a point then stuttered and coughed as if being starved of fuel. Lapped the head on one and fitted new rings to the other. Both ran well afterwards,

Paul

i reduced the size of the main jet as i found a puddle of fuel inside my carb. this has resolved the problem. It look like the carb was flooding.
Thanks for all your advice.
ps. i do get a small amount of backfire when changing down.