BS40 CV carb GT750 jetting for pods and chambers?

[MikeD]

hoping those that who run expansion chambers and have converted to pod air filters on their BS40 CV carbs on the 750 can post their final jetting numbers to help get me in the ballpark initially. If I can avoid ordering a bunch of ascending sized mains and pilots from Sudco that I'll never end up using I'd be appreciative

[RING_DING]

I have Jemco 3-3 chambers with stock airbox. I run 117.50 mains and 45 pilots in all three. My mate Rassie (also on this Forum) had (bike was sold) the same Jemcos with pod filters and was running 122.50 mains and 47.50 pilots. Hope this helps.

[rngdng]

With the BS40 and K&Ns, I only raised the mains one size.



Lane

[MikeD]

With the BS40 and K&Ns, I only raised the mains one size.

stock pipes, correct?

[tz375]

Mine ran dangerously lean with 115 and a touch lean with 117.5 mains 47.5 pilots with UNI filters and either stock OEM or Jemco 3-3 pipes. 125 is about right with race gas with that same set up and probably 122.5 or 120 on street gas.

With 3 into 1 pipe, 115 were pretty close and 117.5 would have been spot on.

Your jetting may be very different depending on how well your pipes work with your porting. More effective pipe/port combos tend to run smaller main jets than expected. Probably related to strength of the suction wave.

Set up your bike on the dyno with exhaust gas analysis if possible.

[rngdng]

With the BS40 and K&Ns, I only raised the mains one size.

stock pipes, correct?

and Jemco pipes....I live at sea level, so that is also a factor.


Lane