Mootsman Posted April 29, 2012 Report Share Posted April 29, 2012 Hello Perhaps someone can help me with my jetting on a fresh rebuild. THE BACKGROUND: On the previous rebuild, I melted the piston on the right cylinder on a long pull down a gravel road. I believe the gas cap vent cap was not allowing enough air into the tank and consequently, not enough fuel into the carbs. The quad was purchased from an individual who lived and rode roughly 500 ft. above sea level Anyway, I want to eliminate any other possibilities so I need some expert advice on my current jetting. Here is my setup: .100 overbore with aggressive MX port by Jeff at FAST. Cool head with 21cc domes Chariot reed cages with Boyesen power reeds stock rubber intakes w/crossover tube PWK 28mm carbs with 148 mains and unmarked pilots Toomey T5 pipes and silencers K&N air filter with outerwear, no lid, and adapter to feed 2 carbs Elevation is 250 ft. above sea level Riding temp is generally 80 degrees F I did a leakdown test today and had I went from 6 psi to 5.5 psi in 6 minutes. spraying soapy water didn't reveal any leaks on the tester or the motor. (Does this sound acceptable?) Is there a way to mic a pilot jet to determine it's size? I have been looking for info but unable to find a diagram that explains jet sizing relative to i.d. Please shoot me some ideas about where I need to be with jetting. Also needle position and air screw position would be helpful too. Thanks in advance Hobbs [/size] [/size] Quote Link to comment Share on other sites More sharing options...
Zwiser Posted April 30, 2012 Report Share Posted April 30, 2012 I'm pretty sure that you are WAY lean. I run 145 mains and my jugs aren't ported and the air box lid is on with pwk 28s and I'm just a little rich Quote Link to comment Share on other sites More sharing options...
Man-O-Steele Posted April 30, 2012 Report Share Posted April 30, 2012 Start with a 48 pilot 155 main on center clip. Quote Link to comment Share on other sites More sharing options...
robert0762 Posted May 1, 2012 Report Share Posted May 1, 2012 I got the same set up. Mx hardcore 4 mill port from hjr. 28 Pwk . Knn no lid but I'm cunning pcs. I'm at 150 rite now and that's safe for winter riding. Kevin told me to run 145. 48. For summer. Quote Link to comment Share on other sites More sharing options...
Mootsman Posted May 2, 2012 Author Report Share Posted May 2, 2012 Well, I ended up ordering some 48 pilots and 150, 152, and 155 mains for tuning. We'll see where it goes. Thanks for the recommendations guys! Hobbs Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.