engine won't rev and smokes

[fajes]

hey,

it's been a while since I've been here!
so it was also a while since I've ridden my S2. when I tried to get her going again she'd go for 100mtrs and die, as in rev drops and dies. checked the carb (22 jetex), cleaned the jets, replaced the fueltab with a new fast flow tab,... tried again, yes she starts, idles, runs! but yet again she ran 100mtrs and the same thing happens...
there's also a lot more smoke than normal.
any suggestions?

since it's been a while: the engine is a standard 1960 Li150 with a GP150 kit, elec ignition and Jetex carb. I used to commute on it, but the last few years it's only been used for the occasional little ride around town.

[coaster]

I've had a very similar issue which was down to a faulty plug

[fajes]

that would be a simple solution, I'll try it after I finish work.

[mick1]

change the fuel......

[fajes]

the fuel was changed when I replaced the fuel tab.

[Timbo]

Stater breaking down....

[bristolmod]

semi blocked jet or passageway in carb

[fajes]

hmmm, I cleaned out the carb and jets.

I do have quite a lot of spit back in the airfilter rubber.

[DigDug]

Breather hole in petrol cap blocked?

[HxPaul]

You say it smokes a lot,is it white smoke,if so it could be your main drive seal thats failed causing your spark plug to become fouled.