Help, strange carb behaviour

[choppersteve1]

Hi all, so my idle is cool, but slightly rich, plug a tad wet, but my revs take a week to drop. So I'm too weak and too rich at the same time. Bloody dellortos, come back Amal, all is forgiven! Any ideas would be very gratefully received. P.s you've guessed it, the carbs a 30 mm phpb.

[Adam_Winstone]

Choke cable slightly too tight, making it rich... but then allowing additional fuel/air mix through when hot, causing it to rev highly at tickover. If you take it for a spin to get it warm, then slacken the choke cable off, do the revs drop?

Is your slide too weak? Needle and atomiser combo so weak that it doesn't shut down well? Got an air leak? Float level poorly set, meaning that rich/weak as float height varies with fuel level? Lots of potential issues but I'd rule out the easy ones first (choke cable).

Good luck.

Adam

[choppersteve1]

Thanks for reply. Set mass clearance on on choke, set float to about 26 mm to ensure not flooding, have reduced float valve for300 to 250. The original issue was 4 stroking its guts out up to 1/8 throttle, the. It was sweet. Went down on pilots up on slides, tried every combo, never had any impact on the 4 stroking. Then went down a size on atomiser, stuck a 40 pilot in and finally clean running . Slight burble just as throttle comes off idle. But revs hang. 2 months and lots of money. Don't rate these carbs at all....

[Adam_Winstone]

Tell me exactly what the setup is and I'll try to help out as much as I can.

[choppersteve1]

Thanks. It's a SIL stage 4 200 gp, 30 mm phpb, ancillotti pipe. Came with 50 pilot, 70 choke, av266/x7 40 slide, 110 main. Blasted away fine. But 'machine gunned ' it's self to bits any time it was in the off idle to 1/8 throttle. Cleaned up instantly like a switched being
thrown . Only thing that finally stopped it seems to be the weaker av264 and 40 idle, although doesn't seem so sharp accelerating now, seems more induction road less speed!!!