FREAKSHOW Posted June 7, 2009 Report Share Posted June 7, 2009 (edited) ok please bare with me this is long winded but I want to put all the info out there to get proper feedback. I have a 2000 shee, when I baught it , it had a real nice drag port done to the cylinders, this thing screamed, 4 mill crank, 5 mill long rod, pwk28s, t5,coolhead 17 cc domes, k&n pods, 157 mains and 48 pilots.It was way to much for me and the riding I like to do. So I wnet to a local atv shop that specialises in 2 strokes. Mainly banshees. I had him port a set of cylinders for me that had a little less top end andd a little more bottom end. He did an awesome job, nice boost ports and the whole job was clean and profesional. So I took them home and rebuilt the top end with the new cylinder and 19cc domes,. Got the engine running ok and off to the coast on vacation I go. this thing ran like crap, I faught the jetting the whole time, dropped from a 157 all the way down to a 142. it ran ok with the 142 butt still has a bog at 1/8 throttle when it idles for a minute and you get back into it. i tried dropping the pilot a coule sizes but didnt seem to cure. so i went back to the basics, checked compression=ok, carbs sync=ok, check for vacume leaks=ok, float level=ok, needles are at the same height, my plug checks looked perfect at a 147 main. but the bog was killing me. so I never got it fixed on my trip and returned home after spending 3 days messing around with this thing. Returned to the shop I had do the port work and explained the problem I was having. His respoce was I will never get those carbs right, the stock carbs are way better. no matter what you do to the pwk28s you cannot jet out all of the boooog. Well thats where Im at . My thaught is there is way to many pwk 28s out there running just fine........ why would stock carbs fix this and pwk 28 cant? why do i have a bog now and didnt before i changed cylinders? are stock carbs even big enough for my engine, will they flow enough air? my current setup is, .020 oversized, 4 mil crank,5 mil long rod, dune porting, v force , t5's, pwk28's , coolhead 19cc domes, k&n pods. it mainly gets ridden at sea level. 142 main and 48 pilot. where should I go from here? more jetting? stock carbs? Is anyone outhere running a simular setup and could give me a good starting point on the jetting? pilot and main.... Is it common to have to change the pilot when the porting is changed even though engine diplacement wasnt? Edited June 7, 2009 by FREAKSHOW Quote Link to comment Share on other sites More sharing options...
RagunCajun Posted June 7, 2009 Report Share Posted June 7, 2009 (edited) Not sure if this will help but i have a 4mil with port work. 30 okos etc. Anyways, 48 pilot, air screw 2 turns out and i forgot the needle clip. I think 2nd from the top. I tuned my pilot/air screw with the bike in neutral. I just let it idle and blimped the throttle till it was nice and crisp off idle. I cant comment on my exact settings on the needle and main because im battling engine trouble. I believe it's a bad CDI or stator. Where's this bog you are talking about? I ran stock carbs on my bike for a very short time. Ran great. You dont need bigger carbs. Edited June 7, 2009 by RagunCajun Quote Link to comment Share on other sites More sharing options...
FREAKSHOW Posted June 7, 2009 Author Report Share Posted June 7, 2009 Not sure if this will help but i have a 4mil with port work. 30 okos etc. Anyways, 48 pilot, air screw 2 turns out and i forgot the needle clip. I think 2nd from the top. I tuned my pilot/air screw with the bike in neutral. I just let it idle and blimped the throttle till it was nice and crisp off idle. I cant comment on my exact settings on the needle and main because im battling engine trouble. I believe it's a bad CDI or stator. Where's this bog you are talking about? I ran stock carbs on my bike for a very short time. Ran great. You dont need bigger carbs. The bog is at about 1/8 to 1/4 throttle, And my question about the carbs was are the stock ones big enough aka 26mm for my engine ? Quote Link to comment Share on other sites More sharing options...
RagunCajun Posted June 7, 2009 Report Share Posted June 7, 2009 yes. Quote Link to comment Share on other sites More sharing options...
MikeNick Posted June 7, 2009 Report Share Posted June 7, 2009 The bog is at about 1/8 to 1/4 throttle, And my question about the carbs was are the stock ones big enough aka 26mm for my engine ? Yes..But your better off with bigger carbs..That motor needs alot of fuel going to it...Your guy telling you the stock carbs are better than the Keihins makes no sense..He doesn't know what he's talkin about.. Quote Link to comment Share on other sites More sharing options...
springer Posted June 7, 2009 Report Share Posted June 7, 2009 i had the same problem a couple weeks ago but with stock carbs. either way, same theory. i just the needle clip up one position and that fixed it all. might be worth a shot... im no expert though Quote Link to comment Share on other sites More sharing options...
pittss1c Posted June 8, 2009 Report Share Posted June 8, 2009 I also would like to disagree. I have a very similar setup (except pipes) Due to some mistakes on my part, I have been pretty far off from time to time on my jetting in both mains and pilots. (too rich always) And I actually have never had a bog. (I have fouled plugs and lost power) So unless maybe you have the wrong needle or something (I never tried that) I don't see how one could say you can't get rid of bogs with those carbs. Will all my errors, I have failed to even create a bog. Mike Quote Link to comment Share on other sites More sharing options...
shanYE west Posted June 8, 2009 Report Share Posted June 8, 2009 Did you do a leak down test on the motor after you reasembled it? What needle are you using and whats the air screw set at? Quote Link to comment Share on other sites More sharing options...
potpye Posted June 9, 2009 Report Share Posted June 9, 2009 It sounds to me like a bent needle, check them out to make sure, I would also check to make sure the carbs are clean including the pilot jet make sure there is no sand or specs of dirt anywhere in that circuit this will effect that 1/8 to 1/4 throttle. Use break cleaner and compressed air. Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted June 9, 2009 Report Share Posted June 9, 2009 I would say the guy that did your port work was not reputable in my book. Come on stockers over pwks? Who knows maybe you just got a crappy port job. Clean the intake bride up, drill a couple of worm holes with the Dewalt. The bogg is probably due to jetting, but you seem dissapointed with the port job. Pwk's are 100x better carbs than stockers. If you want to lean it out in the 1/4 throttle range try a needle that has a larger diameter. Quote Link to comment Share on other sites More sharing options...
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