There is nothing wrong per se with drilling jets but as you may be changing them out from time to time it's not bad idea to have them. I have from 125 up to 180 on the mains, 40 to 58 on the pilots and two sizes of slow air jets & main air jets. Granted I have three engine configurations.

Tom

Whats wrong with drilling the jets? Can then buy correct ones later.
would have thought needles would need replacing though.
Im about to embark on similar thanks to sikyne made manifold for my l18

Do not ream out jets just buy a set of 145's 148's etc or whatever you need. As someone with bike carbs I will say just get the car running. You can get the car 80-90% correct in the garage. After that you just need about 1/2 hour of dyno time to get it spot on. As for shimming the needles do these carbs not a clip that allows adjustment?? I ended up using shorter L1 dimension needles to get them on the middle clip. (FCR carbs). On the pilots with a GX cam it took a 50 pilot jet but with a cam with a good bit of over lap it needed 45 pilots.

Tom

For reading spark plugs see http://www.strappe.com/plugs.html

For tuning BS34 carbs, see http://datsun1200.com/modules/mediawi ... php?title=Bike_Carbs#BS34

i'm thinking of reaming main jets to 142 and shimming the needle with a washer. dose this sound ok?

the thing is that when i bought my 1200 it did not have the intake manifold and i got the bs34's free from a biker friend.

Well run motor in on stock carb then try. Unless you have anothrr motor you can set b them up with. I wouldnt try setting up fresh motor on them

yeah i had the carbs on and the car ran but i had to pull the engine for a rebuild was smoking like crazy. i had warn cylinder walls.

Sorry I can't remember. I didn't bother getting jets I had the existing ones resized.

Have you tried the existing jetting at all?

Lean is safe for lpg lol.