4L0-01 Premix jetting

[nokturnal]

Would a 25 pilot be good enough for a road bike with an airbox? Recently picked up a tracker that I am putting on the street, no pump. Never jetted an LC for premix before.

All my searches have come up with 83+ and 31k carb jetting.

The bike came with a 27.5 pilot and a 160 main, so I am guessing it has never been ridden like this. Had been sitting for several years, mid-conversion to track bike. (I think).

Thoughts?

I put a 240 in for a main jet for now until I get it on the road. Bike is an 81.

TIA

[4l04ever]

I run 25 pilots in my road/track bike. Modified airbox lid. 290 mains.

Double check carbs are 4L0-01 not 4L0-00.

[nokturnal]

Defo 4L0-01.

Good to hear. Years ago I saw quite a large drop in gas mileage on my F2 when I wrongly upjetted the pilot for a Y-boot. I will pop in some 25s when I get them.

Thanks for the info Rob. Which pipes are your running?

[4l04ever]

I am running TSA pipes, ported engine, 40:1 Fully Synthetic Exxol Racing Two stroke oil. Needles dropped one groove to lean it off slightly. My plugs/pistons are chocolate brown, but it is Bournville dark chocolate colour :-) Safe for even the coolest autumn morning.

[nokturnal]

Thanks for that.

I have some TSA pipes in the garage I might put on. They are the originals though, from years ago, so will need to sort the side stand. Right now running stock F2 pipes.