I'm currently running a 1916cc, 120 engle, 009 dizzy, with Kadrons. The engine is brand new only 90km on it.

Current main jet : 135

The engine has developed a stutter from idle to take off. only stutters a couple of time then takes off. This onltysems to happen after about 20min of running.

Should I change the main to 140 and change the idle jet aswell? Whats the best combo for this set up or what else could it be?

[ Edited on 21-4-07 by Bone Collector ]

It wont be the main. Wrong rev range. Could be the idle.
What size are you running now??

The fact it stops after a while makes me think air leak.

A week or 2 ago i changed the rubber boots and manifold gaskets and what a difference that made.
Was stumbling and dieing once the choke came off.
Not now.

[ Edited on 22-4-2007 by Bizarre ]

Give Stan Pobjoy a call at Coffs Harbour he can tell you the jet sizes easy

Have you checked all the gearbox / engine mounts as well and clutch adjustment