Author Topic: A quick jetting question  (Read 2250 times)

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Offline kx5rider

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A quick jetting question
« on: June 25, 2009, 05:08:14 AM »
I know it's probably been beaten to death and I looked at the jetting sticky but still had 1 question. I race a '94 kx500 supermoto and motor wise it's set up with a fmf pipe/silencer, rad intake and a steel liner with a 1 over piston. I usually run it at right about 2200ft but this weekend will be heading over to seattle for a race and they are at sea level and won't really have any set up time. I'm also running a 50/50 mix of trick leaded 114 and 92 mixed with 927 at 32:1.
Right now I'm running 1 clip from the leanest, 160 main and a stock pilot which I believe was a 50. It runs pretty d**n hard right now but could use a little more fuel on top and I'm afraid if I drop 2,000 ft it could get a little lean :-o I was thinkin just getting a bigger main, I got a 165 but do you think that would do it or should I try a 170?
Any help would be greatly appreciated :mrgreen:
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Offline KXcam22

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Re: A quick jetting question
« Reply #1 on: June 25, 2009, 08:44:15 AM »
The 160/50 is leaner than stock, actually I am surprise an SM would handle jetting that lean.  I ran 165/55 singletracking at 2500 ft. At sea level you might find the 168/58 combo better, and move the needle clip down one.  I would suggest that you run a new plug for first practice then plug check your mixture as soon as you can so you can adjust the main before fiirst race. It might be good to show up with a 168 and a 170 just to be safe. Cam.

Offline kx5rider

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Re: A quick jetting question
« Reply #2 on: June 25, 2009, 01:49:24 PM »
I'll have to try that, I got a spare carb so I can have 2 set ups ready to go. I'll have to grab some different jets before i leave.
I don't remember what pilot was in there but I believe it is what came stock. I ran a new plug last session up here and it looked pretty good, just a tad on the lean side.
The other thing is the track I've been running is really tight where this track looks quit a bit faster so I'll be at the top of the motor a little more.
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Offline kx5rider

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Re: A quick jetting question
« Reply #3 on: June 30, 2009, 05:22:41 PM »
Well I ended up throwing a 165 main in and moving the clip one down and it ran strong all day..... gave the 4 strokes trouble down the straight all day:-D
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