Blacksmith Posted June 21, 2004 Report Posted June 21, 2004 Hey Guys, I am running a single 35mm PJ on my bike, using a CV intake. Anyway, after having taken the carb apart several times, and even changing to another carb, I can not get the bike to run on the idle circut. I have tried 38, 48, and 54 pilots as well as everything else I can think of. I have to tighten the cable enough to lift the slide about 1/8 inch to get the bike to idle. Anyone got any ideas? Thanks for the help. Quote
sredish Posted June 21, 2004 Report Posted June 21, 2004 (edited) You've even tried changing to another carb huh? Hmmm... Have you checked the reeds lately? Edited June 21, 2004 by sredish Quote
SDD Posted June 22, 2004 Report Posted June 22, 2004 Did you unplug the TORS plug under the tank? Its the three wired white connector? Another member of this site just put carbs on and this was his problem... he never unplugged the TORS system and when you release the throttle it would push in the switch in the throttle housing causing it to trip the TORS (system still works even if you just unplug the stock throttle switch). Anyway if he wants to let you guys know about this I'm sure he will post if he feels like it. Quote
BenBB Posted June 22, 2004 Report Posted June 22, 2004 Blacksmith, I don't know how the PJ is set up exactly, but you should have a way to set the idle speed, separate from the throttle cable adjuster itself. Sounds to me like the jetting isn't the problem, so much as the idle speed adjustment. Your pilots control mixture at idle, and the airscrews (or fuelscrews, depending on which side of the slide they are on), fine tune the mixture. If you had an erratic idle the pilots could be rich or lean; a real high idle would likely be lean pilots (along with not wanting to start when hot without the choke); difficult starting when cold with the choke on and subsequent flooding is likely rich pilots. All of these can be made worse if the air/fuel screws are way outta whack. Even if the pilot/airscrew circuit is dialed in perfect, it won't idle if you don't have the idle speed adjusted high enough. Some carbs use a screw that hits a ramp on the slide (like stock carbs with the TORS removed) to raise the slide, and increase the idle speed. Your PJ's might use the throttle cable adjuster on the top like you're doing now, I don't know for sure, but if that's the case you need to make sure to adjust the cable at the thumb/twist so that the cable itself has some slack in it. Anyway, see if you can find the idle speed adjustment, find the air/fuelscrews and try to set them in the middle of their adjustment range (if you can back them out 3 turns from seated, start at 1.5 turns out), and pick the pilot jet you think is closest to being right. Then adjust the air/fuelscrew so you get a clean idle and a good off-idle response (doesn't stumble or hesitate right off idle), and adjust the idle speed where you want it. If all else fails you might check the compression and the reeds just in case, along with the intake for any air leaks. Good luck. Quote
Blacksmith Posted June 22, 2004 Author Report Posted June 22, 2004 OK Guys, sredish, The reeds were just out of the bike. They are new Boysons on ported cages. SDD, There are no TORS components still on the bike. None at all. Ben, The idle is adjusted on the PJ carb by turning the choke knob. Having taken the carb apart several times, it looks to me like all the idle speed is really adjusted by simply opening or closing the choke circut. I have used compressed air to check the idle circut a couple of times so I am pretty sure that it is open. The top end is fresh (2 hours on it) and has good compression. Anyway, the real problem is that I think that I am lifting the slide far enough that the bike is running off the main jet circut when idling. As a result, movement of the air screw or changing the pilot seem to have no effect on bottom end performance. Anyone out there got a PJ? Do you have to hold up the slide to get it to idle? Thanks for the help guys!!!! Ben - I will have comments on the FAQ ready pretty soon:-) Quote
BenBB Posted June 22, 2004 Report Posted June 22, 2004 I just checked out the exploded view at sudco.com, I think you're right. I had a similar carb on a 250R and turning the choke knob does adjust the idle, BUT there's also an airscrew. Have you tried going all the way in & out with the choke and airscrew? Just curious, hopefully someone more familiar with it will post... Quote
Blacksmith Posted June 24, 2004 Author Report Posted June 24, 2004 (edited) Wow, No one out there has ever ran a single PJ carb? Edited June 29, 2004 by Blacksmith Quote
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