I bought a new carb, sourced some extra jets, and this is what I've come up with. I live maybe 100 ft above sea level and ride up to 2000 ft and down to a few ft below sea level ( Skagit Valley ). Needle jet and jet needle combo is the trick. Needle jet - 585-P-6 with 9EB Y01-51 Jet needle, 4th notch from top. Main jet 127.5, Pilot jet 22.5, and stock pilot air jet. Needed a longer throttle cable but that was it. This thing now pulls much stronger. I still use a Vortex, so it's pretty quick. I think I'll quit messing for now and just ride and moniter my plug and keep an eye out for soot on my pipe.

 

Have you adjusted the accelerator pump starting and duration timing?

Ride on
Brewster

 

Hey Man, The accel pump is stock settup right now. It begins when I open the thottle but may be ending later than it needs to. I'm following the Mikuni HS40 tuning manual and that suggests to end pump at 3\4 throttle. So, good question. I think the spray is set correct. What do you think? That last 1\4 with no spray? Thanks Not sure I understand what you mean by duration timing, but I'm guessing you mean the end point.

 

Thinking a bit....... Of course that's what you mean.

 

End point and duration seem to be the same thing. Adjust it for the best throttle response.....blip the throttle from idle. The two I've adjusted had too much gas squirting.

Ride on
Brewster

 

Thank You!

 

And make sure the squirt is hitting the needle as it sticks down into the carb throat. The squirter is adjustable in a rotational plane.

newparts, I'm curious where you obtained your part numbers. Just for comparison, I use the P4 needle jet and 9EBY01-50 with needle in the 3rd slot from top. I also use a 17.5 fuel pilot jet with a .09 air pilot jet. Now, my engine has a 300 cylinder instead of 351, so there is a small difference. However, the guys I took the jetting numbers from had 340 kits or something in that displacement range.

Jetting does not have to be always exact between bike, of course, but I was surprised how everything but the air pilot jet was basically the same. My home elevation is about 1700'. My recent trip to Colorado, however, required me to drop to a 125 main jet with the needle in the 2nd notch from the top.

This is a great carb. The performance, tuning latitude, and even fuel economy simply kills the OEM CV carb.