PHBG Tuning - Garelli VIP

Zack Bandit /
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ok folks, I got some questions, setup first, questions second.

Garelli VIP 2 speed

64cc polini

20mm polini intake (necks to 17mm on carb side)

Leo Franconi circuit pipe

75w90 in tranny

150lbs compression


Avanti CDI, factory timing

21mm PHBG

#50 idle

#60 pilot

#90 main

w7 needle, 2nd notch from the top

#40 throttle cutaway

#262AU emulsion

*no filter

Alright, so heres the deal. Bike runs great and starts easy on the stand, need the choke when cold, but that's normal. Operation is normal until it heats up, runs well. After about a mile though, the trouble begins. 1st speed is fine, run through it, plenty of power, shifts late, on purpose, the heavy fluid. Once it shifts into 2nd, it lags through the whole throttle. If I dump it down to about 1/8th throttle and slowly work it back up, it'll pick up, but slowly.

Main jet wise, I've tried super huge jets, dangerously small jets, and everything inbetween, combos with a filter and without, and different filters. The only other idle jet I've got is a #45, it doesn't do any different. Needle position seems to make it worse if I raise (richen) the needle, but the top position seems no different than the 2nd.

It's been suggested to me that heat fade might be my issue, but I'm running a B7 for a long time, with various carbs. Most recently, with a 19mm SHB, and it did fine.

I read in the wiki on this page that throttle slide cutaway is important in multi speed bikes, and that it is particularly important for the 1st half throttle. Could this be my problem?

How about that needle? what about the W7? it seems to be rich, but I've been wrong before.

The plugs come out oily, but when wiped clean they are coloured correctly. I'm assuming the oil is coming from low rpm stuff, idling, slowing, etc. rich? wtf. this carb might kill me.

Later tonight, I'm going to put everything as close to stock as a kit/pipe/carb will allow and give it another go.

so, advice? I'm lookin' at you, Garelli people.

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