power problem

[roadrunnerian]

Hi,
here is some details as requested by sean,it is a stage 4 barrell and cylinder head with a asso piston with 3mm cut off, i am running a 28mm dellorto phbh with a 122 mains jet amd 42mm
fresco exhaust.it has a race crank and uprated springs on the clutch.thanks for your replies so far.

[Dazza]

Have you checked the flow rate? I had similar with a 30mm phbh , it would run perfect until I caned it in top gear, it would backfire and miss until I eased off the throttle to give the carb chance to fill up again, i changed the tap a few times until I found a true fast flow one (camlam) incidently.

[sean brady scooters]

Hi,
here is some details as requested by sean,it is a stage 4 barrell and cylinder head with a asso piston with 3mm cut off, i am running a 28mm dellorto phbh with a 122 mains jet amd 42mm
fresco exhaust.it has a race crank and uprated springs on the clutch.thanks for your replies so far.

i was actually hoping for a far more comprehensive reply than that matey..in order to give us some clues and help us help you.......
for eg..
Tap jet size....?
main jet...........122
pilot jet...............?
Atomiser/diffuser......?
Slide..................?
needle and setting........?
and is your carb fitted with a filter or does it run open with or without hole in panel..........?

[Lazarus]

sorry to butt in Sean but as im paying attention to this post can you explain about the "Tap jet size "
ie: do you mean standard or fast flow fuel tap or something else ?

i was actually hoping for a far more comprehensive reply than that matey..in order to give us some clues and help us help you.......
for eg..
Tap jet size....?
main jet...........122
pilot jet...............?
Atomiser/diffuser......?
Slide..................?
needle and setting........?
and is your carb fitted with a filter or does it run open with or without hole in panel..........?

[roadrunnerian]

hi i think best thing is to nip over to you with the scoot because i am just getting back into it after a thirty year break and a lot of this stuff gone straight over my head.it has a rayspeed quickflow fuel tap and has the rubber air filter bellows with a fram sponge filter on rest of the stuff i am sorry unable to help. thanks for all of your help everybody

[soosh]

Ive had my Saxelby stage 4 with a phbh28 with PM set up as this on the dyno:-
115 main AV264 atom with X13 needle on 2nd clip.Think its 50 slide,cant remember the pilot but think its 55.Its got a 300 float needle valve.On the main,you may wanna start at 120 but i found that too rich and 118 was advised if on a long run and flatout but have always used the 115 and its spot on.Timing is static at 19 degrees.Hope this helps mate.

[roadrunnerian]

thanks soosh may try your settings