Originally Posted by mapbike
The "jitter & Jerk" is perfectly normal at low RPM's on these engines, until the revs come up a little 2 smokes are pretty gutless but after the revs come up to the right point these little gals will start ginning nicely if the carb is jetted correctly and all else is right.
Another thing to remember is that the size sprocket you have on the rear wheel will have a lot to do with how fast you will have to be going under peddle power before the engine will pull the bike on up to speed smoothly
Exactly what I would I have said Shan, well done.
With a direct drive you have no low gear, you'll be lucky to motor at idle through a school crosswalk without jitters, but you have a nice top end.
There are ways to give you a better low end "stay alive" torque, but you sacrifice high end speed speed to do it for the most part unless you go extreme like an Expansion Chamber exhaust.
Just for reference 'the bike' just really doesn't help with problems.
Exact motor in this case really helps bud.
There is a huge difference between a 48 and 66cc motor as far as low end for example.
And then there is motor make itself but I won't go into that ;-}