40idf jetting on 69x88 motor

[axam48ida]

any suggestions on jetting of a small displacement motor with 40 idf's
 motor has a very mild cam, lightly ported heads
 It's not popping or coughing....just lags on low end from intial start
I have F7 emulsion tubes, 115 mains, 160 air and 45 idle
 mid range and top end seem fine

[Rasser]

Your vents plays a big role in jetting...  what size are you running ?

[axam48ida]

28 vents

[alex d]

I'd try larger idles

[nicolas]

i run 28 vents in my 1641

and i have 115 or 120 mains

and 190 air

and idle jets are 50 if i am correct.

not sure at the moment what tubes i have...

[Rasser]

Sounds like you´re sizes aren´t completely wrong.

But i too would try 50 idles or 55, and adjust the floatheight and acceleratorpump.

How about synchronization - is it spot on ?