Carb settings

[racegt50]

21mm phbg clone carb arrived today fitted and it starts up no choke required, BUT it won't rev past 4k rpm when warmed up no matter the needle position. Pulls clean up to 4k then it's like it's got a limiter installed can't even test ride because my pull off is around 5k

it has a 90 main installed needle currently on 3rd setting. Mods are 70cc stage6 street race 2k red torque spring 4.5g rollers open filter and technigas triops exhaust system and a CDI with no limiter.

Using a 17.5mm carb it was stuttering at 5k for pull off just rolling to 10mph gradually getting faster untill got to around 20mph around 8k rpm then takes off like a Tom cat chasing ass all the way to 60mph at wot at 10-11k rpm

I'm awaiting a jet kit of idle jets mains and needles to arrive, wondering if anyone's managed to get the same carb set up so I got a close idea where to start for my engine.

My bikes a generic race 50 was for my son but it's more fun than a bigger bike round round 🤣

[captincvmn]

Do the keys from the smaller carb fit into the new carb?

[Zino]

i ran a 90 in a 17.5 dellorto and a 82-84 in a 19mm dellorto
Both with a un modified airbox
You are running a open filter so you I would start with jetting in the 100's and work your way down

[racegt50]

Jul 22, 2021 18:13:41 GMT -5 captincvmn said:

Do the keys from the smaller carb fit into the new carb?

No the jets from 17.5mm are M6 the 21mm are M5 that was my 1st thing to try before fitting.