Sounds to me like its either running weak (try a larger main jet) or your rubber
pipe does, in fact leak. A 19.19 inlet tube is not an expensive item, just put
the proper one on. If you really can't it would be worth using some sealant of
some sort. A 'scuking' leak is much harder to find than a 'blowing' leak.

Greg

--- In vespasmallframes@yahoogroups.com, "pk50stu" <pk50stu@...> wrote:
>
> hi i got a pk50 with a malossi 110 kit and a dellorto 19/19 carb the problem i
have is do the engine get relly hot and sometime it tick over fine and other
time it seems like someone is twisting the throttle
> when you go along the road at a stedy speed the engine sound like normal when
you give a bit of accelerator it sound like it has a big bore and the engine
sound realy flat then pick up speed quick it has a racing exhaust on it. And
how would i set the carb up and timing as i think it has a flat spot some times.
My mate pk100 dont get hot like mine thanks stu
> ps would it help if i put a 19/19 manifold as its got a 16/19 manifold and a
rubber pipe to make it fit but i am sure it dosent leak any air
>