Hi all

As a newbie to this forum, can I ask my first question please?

I am in the process of doing a ground up restoration on a DT400b and I (in my ignorance) purchase a VM34 hi top carb for the bike. Whilst I (now) believe this is a popular upgrade could someone please guide me as to what size pilot jet, needle jet and jet needle would be best to fit inorder to get it running properly?
Many thanks in advance

Welcome from NZ downunder. Just my warped ideas below but someone should pop up soon with meaningful numbers.
if it's a New 'out of the box' carb i'd just note the main jet number then try it first & see how it runs.
Just feel it through the midrange to be sure it's in the ball park & not too lean by feel--or blubbery rich.
Go easy opening it fully onto the main jet by feel.
If the needle feels ok midrange & then when on full throttle it doesn't gasp while looking for more fuel main jet could be close.
Idle of course should respond either side of 1.5 turns out to be close.
Sorry i'm no help am i but just what i'd do if i had nothing to go by.
Hope someone can come up with numbers for you soon.

Thanks for the response RT 325.
Even Ai and CBT can't agree on jetting sizes, so I was hoping someone, somewhere has been through the trauma of swapping jets etc?

Check service manual. states 6F9, O-8, 40, 160. Note, some of the newer VM carbs use radically different jetting especially for the main. IE, a 260 could be the right starting point. They are not the same carbs.

Thanks for the response Pabdt

I will order those jets and give it a try,