Kit car CBR900 - looking for help.
i've got an MK Indy kit car wiht a 1994 Blade engine.
It's been dyno jetted by company that races this engine in cars, but im having trouble getting it running perfectly since then and have literally run out of ideas.
Symptoms are - Stutter/hesitation/jerky at 6000rpm on constant throttle.
I can drive through this on open throttle, but on approx 1/8 - 1/4 on constant throttle (cruising) its rough and jerky.
Settings are -(tried and tested setup on many Blade kit cars)
Needle 2nd clip from top
Air correctors blanked off
Mixture 2.5 turns out
I have raised the needle without much change.
Tried this in another set of carbs (without blanked air correctors) no change
Coils,leads,plugs all changed.
Variations of airbox openings.
Everything is fine otherwise and it pulls like a train - but constant throttle at approx 6,000rpm is hesitant and its driving me mad.
Plugs look as if things are good or slightly lean if anything.
Im running a Ackrapovic which is essentially straight through, and get some pops on lift off.
Any suggestions would be great.