moparmadman40 Posted February 21, 2014 Report Share Posted February 21, 2014 ok, so i've finally got my bike running with the single tm-38 carb. i started off with a #25 pilot and i couldnt get the thing to run right without turning the idle up, seemed very rich but my highest idle was with the air screw turned all the way in. decided that the smoke don't lie and i put in a #20 and the bike seems to run better, but i turned the throttle all the way closed and the bike was still idling way high, highest idle seemed to be with the air screw all the way closed, and it is still smoking like its rich at idle. bike also had a pretty hollow sound and hesitation when revving off idle. This doesnt make sense though, if it was rich, turning the air screw out should have made it better not worse. can anyone comment on this? bike is a 4 mil, ported 198/130, single tm-38, approx 3500 ft elevation and 32 degrees Farenheit Quote Link to comment Share on other sites More sharing options...
fastbanshee8 Posted February 21, 2014 Report Share Posted February 21, 2014 Turning the air screw all of the way in is cutting off the air to the idle circuit, so when it's still idling high that means it's still lean. I'm running dual TM-34's, and I've got a stock cylinder 4 mil, ported, CPI's, and pods, and I'm running 40 pilots. Once you get your pilot right, your air screw will be 1.5-2 turns open. Quote Link to comment Share on other sites More sharing options...
dirtydownunder Posted February 21, 2014 Report Share Posted February 21, 2014 IM running 50 pilots in my 34tms on my cub. So id say you are lean on the pilot. That single carb is not a good choice for your cub. Quote Link to comment Share on other sites More sharing options...
moparmadman40 Posted February 21, 2014 Author Report Share Posted February 21, 2014 i really thought about it all night and yes i should try a larger pilot. it just didnt jive with what i was seeing in the exhaust and plug. i'll jump it up and see how it works. i started thinking about the hollow sound when revving off of idle and i now think that it was a lean bog because it didnt sputter. I only had room for a single carb, this isnt actually a banshee. you can check out my other post in jetting about a tm-38 single starting point for a picture. Quote Link to comment Share on other sites More sharing options...
banshee jump Posted May 4, 2015 Report Share Posted May 4, 2015 Turning the air screw all of the way in is cutting off the air to the idle circuit, so when it's still idling high that means it's still lean. I'm running dual TM-34's, and I've got a stock cylinder 4 mil, ported, CPI's, and pods, and I'm running 40 pilots. Once you get your pilot right, your air screw will be 1.5-2 turns open. what is ure jettingn with those tm34?? What is Ure elevation? Quote Link to comment Share on other sites More sharing options...
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