low end jetting
#1
06-20-2009, 11:29 PM
Join Date: Jan 2009
Location: caroga lake ny
Posts: 55
low end jetting
ok all you jetting gurus...need some advise,i just put a new hmf on my 07 klx 250,and love the low end torque!....i want to rejet but dont want to lose the low end,looking for recomendations,so far everything is stock except the pipe,i usually only rev at around 5-6 k between gears and never over 8k....thanks
#3
06-21-2009, 12:37 AM
n1tc needle (put the clip on the 3rd from the top slot to start), 128 main jet, fuel screw 1 1/2 to 2 turns out. Your stock pilot jet should be fine. Test ride it to see how she works then make adjustments as needed.
Last edited by lcpl0331; 06-23-2009 at 10:36 AM.
#4
06-21-2009, 10:52 AM
Join Date: Jan 2009
Location: caroga lake ny
Posts: 55
thats interesting,,,i thought you could jet for more top end or low end....cool!
#5
06-21-2009, 10:56 AM
Join Date: Jan 2009
Location: caroga lake ny
Posts: 55
Thanks....thats kinda what i was thinking,just a mild jetting at first....i plan on getting the kdx 220 snorkel as well,cant stand that noise under my *** with it off!..lol.......yea i know Marc.....the loud pipe thing and all!...lol
#6
06-21-2009, 02:00 PM
http://www.yellowdogracing.com/techstuff.htm
Try that, it tells you how to properly tune your carb. I think it's for 2 strokes, but works in the same basic way. Only the mixture screw works opposite. In a 2 stroke, the mixture screw adjusts air, in a 4 stroke the mixture screw adjusts fuel. And thus the 2t out leans it out and in richens the mixture, and a 4t out richens the mixture and in leans it.
Try that, it tells you how to properly tune your carb. I think it's for 2 strokes, but works in the same basic way. Only the mixture screw works opposite. In a 2 stroke, the mixture screw adjusts air, in a 4 stroke the mixture screw adjusts fuel. And thus the 2t out leans it out and in richens the mixture, and a 4t out richens the mixture and in leans it.
#7
06-21-2009, 02:06 PM
I had the same problem. I rode around with the snorkel off for a month or so but I finally broke down and installed the KDX snorkel. Mucho bettero
#9
06-21-2009, 05:25 PM
I think that is more so for a 2 stroke, and I don't think it really changes the power band it just makes for less plug fouling and throttle response if if tend to ride in the lower rpms(ie tight woods vs wot for mx/sx)
#10
06-22-2009, 12:57 AM
Good jetting makes the bike perform better everywhere.
However, things throw good jetting off, such as elevation, humidity, or any kind of air changes. I would obviously assume fuel changes would change the air/fuel mixture as well.
Think of it as trying to get perfect air/fuel mixture. Whenever you modify, you're supposed to re-jet. Or at least check for mixture. Especially with things like different exhaust, new air filter or air intake mod's..
However, things throw good jetting off, such as elevation, humidity, or any kind of air changes. I would obviously assume fuel changes would change the air/fuel mixture as well.
Think of it as trying to get perfect air/fuel mixture. Whenever you modify, you're supposed to re-jet. Or at least check for mixture. Especially with things like different exhaust, new air filter or air intake mod's..