Bonneville America Forums Forums Technical Forums Performance Mods What is the Keihin series # for our pilot jets?

21? 22? Something else?

I would pull one out and measure it's length.
This chart should help.......

Click Here

According to chart, it would have to be either the -22 or -25B

Hope this helps.

PS....after looking at Dinqua's carb site, it looks to be the -25B series.

Our pilot jets are 15mm in length.

What is the difference between the N424-25 and the N424-25B jets?

Incidentally, our main jets are 8mm in length.

And that begs the question: Which are our main jets? N424-36, 99101-393 or N424-27? And what is the difference?

If you look down to the bottom of the chart is shows what model designation carb they fit.

-25B and 393 are for the CVK carb. Yamaha dealer should have these.

The realm of possibility for the jetting of our stock carbs is:

Slow Jet (N424-25B)
35, 38, 40, 42, 45, 48, 50, 52, 55, 58, 60, 62, 65, 68, 70, 72, 75, 78, 80, 82, 85, 88, 90, 92, 95, 98.

Main Jet (99101-393)
60, 62, 65, 68, 70, 72, 75, 78, 80, 82, 85, 88, 90, 92, 95, 98, 100, 102, 102, 108, 110, 112, 115, 118, 120, 122, 125, 128, 130, 132, 135, 138, 140, 142, 145, 148, 150, 152, 155, 158, 160, 165, 170, 175, 180, 185, 190, 195, 200.

Tech Vault time??