carb

ultrafast30

New Member
Jan 17, 2010
45
0
0
so, I built a 240 blaster,ported, 100 octane setup with CPI pipe. I have a 34 mm pj carb. really dont like it but I am getting closer. It stumbles on bottom I ordered a needle and a smaller pilot jet, and that should help. Motor is rich through the low to mid range and Runs great on top!! What are some of you guys running? is there something more modern out there.
 
tell us what jetting your running now, i'm playing with that same "hard to tune" carb,
i'm at a 50 pilot and 155 main, it's a little rich on bottom, but it's still lean on top
 
tell us what jetting your running now, i'm playing with that same "hard to tune" carb,
i'm at a 50 pilot and 155 main, it's a little rich on bottom, but it's still lean on top

Yeah, I'm fairly happy with my PJ, but they are notoriously hard to tune on the bottom, although you really shouldn't have any need for that part of the throttle range anyway...:D:D
I'm at a 42 pilot, and a 145 main, but I ride at 4000-6000 ft. I've heard a good rule of thumb is one jet leaner for every ~1000 ft above sea level. Looks like you and me have similar jetting (adjusted for altitude of course ) Awk.B)

Mine idles nicely, but it's a little burbly just off idle to about maybe 1/8 open? I'm happy enough with it. I'm thinking about a 33mm PWK though.

Edit: to the OP - don't confuse low end RPM with low throttle opening. They are different. Also, if you haven't already, try dropping your needle. Mine is all the way down, and that cleaned up the response/low throttle running considerably.
 
i use a 34mm pj with the mods in my sig and right now im running a 170 main and a 48 pilot with no lid. it is definately a bit rich but it rips so good i dont mind. i guess the machine prefers to be on the pipe but i still can chug through the woods just fine.
 
I have that carb on a BB. If you look the carb up on the net you'll see that it is a low to mid carb. I've only owned mine a few months now but it has always been crisp off idle. Being a low to mid carb. I would think you could dial in the bottom ok. I need to pull mine apart to educate myself. I'm only 200' above sea level and she hauls ass.
 
I am at 58 at the bottom and 158 at the top. I spoke to the guys at carb parts warehouse and then to Denny at Flotek. Much of the problem is the needle. I have an EEG needle and both recommended a CLG needle with a 52 pilot. In addition a 6.0 slide was recommended which I have. I am extremely strong on top (and a bit rich)although I could be bleeding over from the big pilot. I will need to recheck when the new pilot and needle go in.
 
The guys at CPW really know their carbs. If you need anything these guys know it when it comes to Mikuni or Keihin carbs.