Hey guys,

i seem to have a small problem that i cant get rid of.
The problem is, i have a flat spot through the rev rangem at about 2000 rpm when light throttle is applied, if i apply slightly more throttle, i can get through the flat spot, then drop back to orriginal throttle position and it will continue up the revs on its merry way.

To try and fix this, i have:

Changed spark plugs
Fuel filter
and inspected the dizzy cap (without removing it) for damage.

What could this be and how do i fix it??

Thanks

PS. Ive searched