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Discussion Starter · #1 ·
Great site, lots of good info. My childhood dream has finally come true, a brand new bike! Now if I can only get the jetting correct so I can stop fouling plugs.
I need to go one needle jet leaner, if I am #1 on a NALF what is the next clip position leaner on a NALG.

What is the proper float height?
Any tips on getting it right would be appreciated.

I have only been riding off road, I want to learn how to ride before I try a track. The owner's manual says to rebuild 90% of the bike within ten races, is that necessary for trail riding?

Thanks.
 

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Mike626 said:
1. Great site, lots of good info. My childhood dream has finally come true, a brand new bike!

2. Now if I can only get the jetting correct so I can stop fouling plugs.
I need to go one needle jet leaner, if I am #1 on a NALF what is the next clip position leaner on a NALG.

3. What is the proper float height?
Any tips on getting it right would be appreciated.

4. I have only been riding off road, I want to learn how to ride before I try a track. The owner's manual says to rebuild 90% of the bike within ten races, is that necessary for trail riding?

Thanks.
1. congrats :p its a great feeling.
2. clip position #1 is the TOP GROOVE = LEANEST (least amount of fuel)
clip position #5/6 is the BOTTOM GROOVE = RICHEST (greatest amount of fuel)
3. float height should be whatever the service manual calls for
4. if you are RACING the bike then thats the manufactures "RECOMMENDATION" time period before a top end rebuild. if you are just trail riding then ride it till the top end is too noisey to be safe (worn cylinder so the piston rattles around in the bore) too hard to explain.
5. whats your elevation ? if you had a service manual you would have a table explaining what to change to compensate for your altitude/temp.
you will prob. have to change your air screw (come out to lean the mixture) and drop the needle (leaner) and go to a smaller main jet.
good luck
 

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"I need to go one needle jet leaner, if I am #1 on a NALF what is the next clip position leaner on a NALG."

I'm a little confused by your statement here..what makes you think your needle position is not correct at position #3 ? The four positions of the jet needle are determined from the top of the needle. The default position is position #3 and rarely needs to be changed. Here are the three jets & their respective areas of performance:
pilot jet--idle to 1/4 throttle
needle jet..1/4 throttle to 3/4 throttle
main jet...3/4 to full throttle.
90% of jetting problems occur in the 3/4 to full part of the band, that is, the main jet's domain.

If you have a performance problem like cutting out at full throttle or slightly less, a fatter main jet will normally clear it up. If the problem is occurring at higher elev than 1200' it could be too rich & a leaner main jet will eliminate it.
In any case, if the bike has enough hours on it to be broken in and the fuel/oil mix is not overly rich, your best bet is to do a proper & thorough test ride & plug read to really eliminate guess work and see what, if any, re-jetting is needed.
BTW, I wrote a tutorial several years ago on test riding & another on plug reading for correct re-jetting. I t contains a photo of a plug from a correctly jetted engine. You're welcome to e-mail me for it if you feel it would help you
 

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Discussion Starter · #4 ·
More info

I do most of my riding between 6 and 10,000', for most of the season it is around 85+ degrees. When I had the bike jetted after break in, they put the clip at 1 up from stock, which leaves it at #1, a 155 main jet, and 52 pilot; the shop however is at 4500'. If I use the chart in the owners manual, my correction factor for my summer riding would be a .94-.92, that is why I was asking about the change on the Needle Clip. I would say the bike has run it's best when I went to Moab, which is lower in elevation, and that weekend it was in the 60's. I left the jetting alone and it ran perfect all weekend, Moab is awesome!

The plugs are always Jet Black, sometimes wet. The filter is clean, oil mix is correct.

I cannot get a service manual for the bike, the local shops tell me they are not out yet, and they are not willing to give me much info.

Thank you much for the info!
 

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With such a wide variation in elevation, I doubt you will find any jetting combo that will be spot-on everywhere. You could always carry a couple of leaner main jets for the higher elevations. Most Keihin carbs have an access bolt to the main jet under the bowl so it's a no brainer to switch main jets. I would still do a test ride/plug read at the elev you ride the most with the needle in the default slot (#3 on a Keihin} and get the main jetting correct if it is off. It is always best to re-jet the main first with the test ride at 3/4 to full throttle in any gear appropriate...the engine doesn't know gears..only throttle openings. Then if a bog or hesitation occurs at the 1/4 to 3/4 range the needle could be raised or dropped accordlingly. Unless you do a majority of riding in the idle to 1/4 throttle range, the pilot won't affect anything above that.

The area of the plug to read is the ground electrode and the insulator all the way down inside the plug. The ring on the end of the threads will always be black regardless.
 

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Mike626,
You need to change your pilot jet to a 48 or even a 45 if you are riding 6000 to 10000 ft. Also at least a 152 main. And probably a 148 or 150 depending on temp. The nalf needle in the top position should be good to 7500 ft. If you want to try a leaner needle go to a naff which is exactly 1/2 clip leaner. I live right down the highway from you near SLC and I'm running a 48 pilot clip in top pos and a 152 main and I ride everywhere around here with no problems. Even had the bike on a dyno with an o2 sensor and found my jetting to be just about spot on.
 
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