fxstbi Posted March 26, 2016 Report Share Posted March 26, 2016 (edited) I just bought a like new '15 300 that the original owner said has never been touched. It has felt and sounded lean since I've had it so I pulled the carb and the jets that were in it were 128 main and 42 pilot. The manual that came with the bike only covers up to 290 size engine size and stock for a 290 is a 125 main and a 48 (shown in the specs). Can anyone tell me what is stock on a '15 300 so I can be sure of what I'm supposed to have? I would like to have the stock clip position too if you know it. Many thanks! Edited March 26, 2016 by fxstbi Quote Link to comment Share on other sites More sharing options...
copemech Posted March 26, 2016 Report Share Posted March 26, 2016 go with the 125/48 Quote Link to comment Share on other sites More sharing options...
fxstbi Posted March 28, 2016 Author Report Share Posted March 28, 2016 I changed to 125/48 and the bike runs much better! Thanks copemech. Quote Link to comment Share on other sites More sharing options...
fxstbi Posted March 30, 2016 Author Report Share Posted March 30, 2016 I finally got this bike dialed in and it runs great. I'm posting one more time just for anyone's future reference. The carb is set for 800' MSL, temp was 60 degrees F. 125 main & 48 pilot, stock JJH needle with the clip in the bottom groove, air screw one turn out. I expect the a/s might need tweaking as the temps climb into the 90's. It took several attempts to get where I am now but it was well worth the effort. I've not done much needle/clip changes on any of my bikes in the past but I saw dramatic changes in how the bike runs in the midrange making those changes. I think those changes are most noticeable on a trials bike because of the controlled use of throttle compared to my race bikes where I am accelerating and passing through the midrange going to WOT. Quote Link to comment Share on other sites More sharing options...
copemech Posted April 1, 2016 Report Share Posted April 1, 2016 Good to hear! Be carefull, as it is likely a lot quicker! Quote Link to comment Share on other sites More sharing options...
cord Posted April 8, 2016 Report Share Posted April 8, 2016 Think i'm going to buy some jets for my '15 300 and have a play. I've already fiddled with float height as i've had problems with it leaking fuel. (Float wasn't shutting the valve) Currently the revs drop off on VERY steep descents, i think this is related to the float height as it can be made better by setting the fuel height lower (Is it possible fuel was spilling out of float bowl and making it excessively rich??) Also after a long hard (more than 20 seconds-ish) WOT the revs take an excessively long time to drop? Any ideas? I know very little about carbs (i was brought up with a laptop and injectors!!) so any help at all greatly appreciated. Quote Link to comment Share on other sites More sharing options...
copemech Posted April 10, 2016 Report Share Posted April 10, 2016 Ck the blog on the Splatshop website for float setting procedure. Quote Link to comment Share on other sites More sharing options...
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