My picco .28 runs a long needle carb - methinks the .26 does as well.
They are a 100% prick to tune, but once you get them right they are a real nice carb.
Forget normal tuning, tune the low speed first - with a long needle carb the low speed meters fuel for 75% of the throttle opening, high speed only chips in at WOT.
Don't try to tune with a pinch test, set you gap to .75-1mm, & lean off the low speed 1/8 of a turn at a time until the car will launch clean without bogging or rough running, once you've got the low speed around the mark lean off the high speed untill the motor pulls clean at WOT.
Then go back & redo the low speed.
If in doubt make sure it's rich on both low & high speed needled before you start.
On thses carbs the low speed affects the high speed a lot more than a 'normal' carb, if it's rich on the low speed no amount of leaning off the high speed will get it running right at full throttle.
By the same token if it's lean on the low speed you will not be able to get enough fuel in from the high speed to get it right at full throttle.
Low speed must be pretty close first & you will have to go back & forth between the 2 a few time untill you get it pretty good.
Those carbs get better economy (longer run time), better part throttle response, a better fuel curve righ through the rpm band & hold a tune much better - at a cost of being a PITA to tune!
jks
