Rejetting a '77 gs400

[charbot]

I have a '77 gs400 and cant find a jet kit. It has stock carbs (BS34's)- PO put on a 2-1 exhaust and replaced the airbox with a single pod and pvc tee fitting(sprayed black of course) connected to the carbs. it has never been rejetted. Not sure where to start. Does the 1-2 pcv/pod airfilter function basically like the stock, or would I need "stage 3" (wouldnt mind mind ditching it and installing 2 pod filters, though)

any tips/ suggestions for rejetting my bike or links to where I can get the appropriate kit?

Thanks

[charbot]

for a starting point here are the stock specs:
main jet #112.5
pilot jet # 22.5
jet needle #4f23-3 (I havent been able to find this one on the replacement charts, is there a newer number?)
-ring on the middle clip


Thinking I should lower the ring one notch
main jet- around 120 if I have 2 pods, maybe 117.5 if I stay with the single?
open the air screw about 1 turn ....all just a guess.

[charbot]

Actually, having trouble finding any parts for this carb. Anyone know if any other mikuni models have the same jets or where to look? Z1 only seemto have stuff for vm

[Big T]

you can always order jets from

https://www.jetsrus.com

Needles -? does yours have height adjustment?

[charbot]

I dont think they have stuff for mine.
This is the only thing Ive found so far:http://www.650central.com/carb_oem.htm

[pete]

Try Sudco.

They have a PDF that has pictures and dimensions of all the Mikuni jets etc. so that should help you work out if you can get them or not...

[Big T]

I dont think they have stuff for mine.
This is the only thing Ive found so far:http://www.650central.com/carb_oem.htm

A BS carb is a BS carb - the jets are all the same standard

http://jetsrus.com/a_jet_kit_street/suzuki_450_GS450S.html