F15C stuttering when quickly going to full throttle

[gcrothers]

Like the subject says.

I can run the engine fine as long as I gently go to full throttle. But going from tickover to full ahead quickly causes it to stutter and sometimes choke out.

I've cleaned the carb, both jets and nozzle numerous times using ultrasonic bath and dried with compressed air. All airways were blasted through with air.

I've checked for vacuum leak around the carb and manifold by spraying brake cleaner and no change in revs found.



I'm at a total loss.. anyone any suggestions apart from cleaning yet again. ( 10th time)

 

[racerone]

Hook up a timing light one cylinder at a time.----Observe the flashing as you accelerate.

 

[gcrothers]

Hook up a timing light one cylinder at a time.----Observe the flashing as you accelerate.

I'll probably not get that done until next Monday... What should I be looking for... I've new plugs fitted as well BTW.
Valve Timing belt due for replacement so I'll do that as well.

 

[racerone]

If the flashing ;light is not steady , there is an ignition issue.