Trying to tune my G80CS, 389 monobloc.
Currently running 260 main, 25 Pilot, 106 Needle Jet, 3 1/2 Throttle Slide, and needle in position 2.
Problem: Flat spot when changing up gears as soon as you let clutch out and try and accelerate.
Bits and bobs done:
1. Checked pilot mixture and all systems ok.
2. Moved needle up and down and 2nd ring from top of needle seems best so far. Top position leans out too much, but flat spot nearly gone.
3. In needle position 2, I removed gauze from bellmouth, and it improved things slightly in acceleration, but only maybe 10-15%.
4. When it 'bogs', if you throttle on, it just bogs more but eventually gets going after coughing a time or two.
4a. If you hold it in the 'bogging' area of the throttle, it will eventually raise revs enough (in say third) to move to a higher rev range and then takes off like a skud missile.
Seems that in 1st, and to a slightly lesser degree, 2nd gear, it revs easily through the flat spot, unless there's a hill involved.
Am I to assume, that a Throttle slide of say, 4 (over my current 3.5) would let more air in, and allow the needle to raise a notch to even out, and probably fix the issue?
Or do I have my wires crossed?
Further info:
1. Seems to pull well with throttle WO.
2. Seems to idle as good as it should.
3. Above 1/2 throttle seems to pull well - unless a hill is involved and flat spot has stopped progression to more open throttle.
Cheers for any help, got a rally coming up and want to get it sorted.
