T_Shee Posted January 24, 2010 Report Share Posted January 24, 2010 my bike had 35 pwk's when i got it which i traded for 33's and then down to 28's. i never had any idling problems with either of the first two sets of carbs. but now with the 28's im having a hard time getting it to idle down right. i got the bike dialed in and running well with good throttle response and power throughout. it will idle all day long just fine but when i hit the throttle to rev it up and let off it takes it like 10-15 seconds before it comes all the way back down to idle. at first i thought it was the slides not returning right so i bought new springs and still the same thing. so now im thinking maybe it is lean on the pilot but im running 50 pilots (seem rich to me) and when i adjust the air screw it makes no difference. i have some 45 pilots i put in but it seems way too lean because it makes it run like crap on low end. my settings are 50 pilot 150 main n68a needles on middle notch air screw 1/2 turn out (ive tried it everywhere from 1/2 to 2 1/2). i just did a leakdown test and everything was good there. i have a cleanup port on .030 over bore, k&n pods, dmc 916 exhaust, 155 lbs compression, +5 timing, 700ft eelevation. any help would be appreciated. thanks Quote Link to comment Share on other sites More sharing options...
LiftdT4R Posted January 24, 2010 Report Share Posted January 24, 2010 Hmm, that's usually a slide issues. Because when the slide and needle come back down they effectively close the main jet and cut off fuel. Do the sledes go up and down easy? You can apply a light coating of grease to the sldies and it should make them slide inside the carb much easier. The throttle cable may also be getting hung up somewhere too. It is also possible that you may have an air leak around the carbs/filter/intakes, that is pulling in air from the outside. When the bike is at idle sparay some starting fluid around the intakes and seals and see if the bike revs up. Quote Link to comment Share on other sites More sharing options...
ClimbAnyHill Posted January 24, 2010 Report Share Posted January 24, 2010 Thinking your cable is getting hung up on.. These carb springs have more than enough power to push those slides down. I have the same 28's without probs.. Wish I was that guy you traded the 33's for! Quote Link to comment Share on other sites More sharing options...
T_Shee Posted January 24, 2010 Author Report Share Posted January 24, 2010 well i origianlly thought it was the slides not coming down right also. but yesterday i had the pods off and pushed down on each slide with my finger while it was idling up and it didnt make any difference. i also put my hand over the end of each carb to kinda bog it down and then it would drop down to a perfect idle. i can do the same with it in gear and let out on the clutch a little to bog it down to idle. i will double check the slides real well to make sure they are dropping right but i think they are. climbanyhill, what size pilots are you running? Quote Link to comment Share on other sites More sharing options...
AKheathen Posted January 25, 2010 Report Share Posted January 25, 2010 your idle is set way too high. the pilots are rich enough to lugh the ehgin back down. i bet it smokes a bit at idle, too. get it warmmed up an mak it do it again. as soon as the idle sticks, then turn it down real quick. that will be closer, and try the airscrews adjustment.....probably step down to a 48? that would be the next pwk pilot, right? other than that, i would have to say to rough up the carbs where they seal on the intakes and make sure they are getting a good seal there... Quote Link to comment Share on other sites More sharing options...
shanYE west Posted January 25, 2010 Report Share Posted January 25, 2010 That dont sound like the right needle.. Kiehin uses three letters like DEK or EGK stuff like that.. I'd find out what the factor needle is supposed to be and start with that.. Its been along time since I've used the 28pwks.. but I know that isn't the factory needle. Even with 50 pilots.. you still could be lean on the pilot.. I would normally say a air leak could be the problem but.. you said you've used other carbs with no issues.. but.. Couldn't hurt to do a leak down and rule it out. If the engine does return back to a normal idle rpm.. it just takes longer then normal.. I dont think it would be idle screws. Thats a sure sign of a lean condition. Quote Link to comment Share on other sites More sharing options...
T_Shee Posted January 26, 2010 Author Report Share Posted January 26, 2010 That dont sound like the right needle.. Kiehin uses three letters like DEK or EGK stuff like that.. I'd find out what the factor needle is supposed to be and start with that.. Its been along time since I've used the 28pwks.. but I know that isn't the factory needle. Even with 50 pilots.. you still could be lean on the pilot.. I would normally say a air leak could be the problem but.. you said you've used other carbs with no issues.. but.. Couldn't hurt to do a leak down and rule it out. If the engine does return back to a normal idle rpm.. it just takes longer then normal.. I dont think it would be idle screws. Thats a sure sign of a lean condition. ya lean is what i was leaning toward from the beginning. i have another set of intakes i will try. i did a leakdown test and everything was good but it could be leaking between the carbs and boots maybe. the needle is from cascade. they claim it is better for pwk 28 carbs. i just put these needles in, my old needles were eek i think. but it didnt make any difference when i put them in. when i adjust the air screws it affects the way the bike runs but doesnt change the idling issue. i really dont think the idle is set too high because once it comes down to a good idle it will idle for as long as i let it as smooth as can be. when i turn the idle screws out a little it starts idling really low and will die and vice versa when i turn them in. i will check some more stuff and see what i find. thanks for the ideas guys keep them coming. Quote Link to comment Share on other sites More sharing options...
T_Shee Posted January 26, 2010 Author Report Share Posted January 26, 2010 it smokes at idle when cold. but barely any noticeable smoke at idle when warm Quote Link to comment Share on other sites More sharing options...
shanYE west Posted January 26, 2010 Report Share Posted January 26, 2010 I'd jump to a 55 pilot for shits and giggles.. see what happens. Quote Link to comment Share on other sites More sharing options...
T_Shee Posted January 26, 2010 Author Report Share Posted January 26, 2010 i may have some 55 or 52 pilots come to think of it. ill try them and see what happens Quote Link to comment Share on other sites More sharing options...
T_Shee Posted February 2, 2010 Author Report Share Posted February 2, 2010 tried some 55 pilots i had and made no difference. so i swapped out my intakes and that was it! coming back down to idle pretty well now. i just got to swap the pilots back out because its def. rich on the pilot now lol Quote Link to comment Share on other sites More sharing options...
shanYE west Posted February 2, 2010 Report Share Posted February 2, 2010 chalk another up for a classic air leak. Quote Link to comment Share on other sites More sharing options...
T_Shee Posted February 5, 2010 Author Report Share Posted February 5, 2010 lol ya, makes it a pain when it doesnt show up on a leakdown test. i guess my tester seals inside the boots better than the carbs Quote Link to comment Share on other sites More sharing options...
AKheathen Posted February 5, 2010 Report Share Posted February 5, 2010 i scuff the carbs and rubber for that reason.......and install as warm as possible..... Quote Link to comment Share on other sites More sharing options...
Ieat4strokes Posted February 11, 2010 Report Share Posted February 11, 2010 T Shee are them the same 28s you got from me a while back? Quote Link to comment Share on other sites More sharing options...
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