Pepto_Bismol
08-07-2005, 06:34 PM
I have spent more than 10 hours researching my jetting issue. (Yes, I've been to Gordons site too). You name it, I've been there.
Settings:
Big Gun Evo X Full Exhaust
Holes drilled in Air Box Lid (to simulate HRC)
Cut intake and drilled 3 way port (Open the R up on a budget)
Stock pilot
Dynojet Kit, Clip on #3 (needle)
Started with 175 Main.
Symptoms:
Good low to midrange (what I consider normal)
But 1/2 to WOT, the quad surges and sputters (cuts in and out).
Definition of lean and or rich seems to be close for my symptoms , So since everyone else seems to be running 175 to 185 main, I could have swore it was too lean.
Does not seem to be the case. I went up to a 180, and the symptoms remained. In fact, pulled the choke, and it got super bad, so then (from all indications), I thought it was too rich. Indeed, the spark plug had fluffy charcoal deposits.
Long story short went all the way down to a 165 main, and it runs great. No more throttle chop. (At 170 main, there is a slight hint of stutter on occasion, but totally disappears at 165)
I did 3 spark plug chop runs, and each time, the spark plug came out white as snow. No indication of overheating, and indeed, there is even a small rainbow film near the base of the ground strap indicating perfect timing (although I have absolutely NO carbon deposite ring at the bottom base of the porculian).
The only thing I can think of is that is it hot as hell here (Phoenix AZ, about 106 today, averageing 3000ft altitude), with a bit more humidity than usual. Both conditions add to thin air, meaning it is easy to "get rich quick". As a matter of fact, I performed a "correction factor" found here:
http://www.motocross.com/motoprof/moto/mcy...01/carb101.html
And it seems like for my riding conditions, if I wanted to use a 175 main, corrected, would be about a 165 main.
The only bummer I have about it is that my freind, with the exact same setup, runs a 175 main, with no problems, And I see most ppl have at least 180 on here (even recommended for jetting with my setup).
Any information you might have will be helpful. (For example,anyone else running a smaller jet setting with NP?)
I am concerned about being too lean, but what can I say, it runs perfect now. Besides, going up or down a couple of jet sizes should put your quad in danger of detonation that soon, would it?
Thanks in advance.
It is a dynojet kit, so please include what type of hardware you are using too.
Pepto :cool:
Settings:
Big Gun Evo X Full Exhaust
Holes drilled in Air Box Lid (to simulate HRC)
Cut intake and drilled 3 way port (Open the R up on a budget)
Stock pilot
Dynojet Kit, Clip on #3 (needle)
Started with 175 Main.
Symptoms:
Good low to midrange (what I consider normal)
But 1/2 to WOT, the quad surges and sputters (cuts in and out).
Definition of lean and or rich seems to be close for my symptoms , So since everyone else seems to be running 175 to 185 main, I could have swore it was too lean.
Does not seem to be the case. I went up to a 180, and the symptoms remained. In fact, pulled the choke, and it got super bad, so then (from all indications), I thought it was too rich. Indeed, the spark plug had fluffy charcoal deposits.
Long story short went all the way down to a 165 main, and it runs great. No more throttle chop. (At 170 main, there is a slight hint of stutter on occasion, but totally disappears at 165)
I did 3 spark plug chop runs, and each time, the spark plug came out white as snow. No indication of overheating, and indeed, there is even a small rainbow film near the base of the ground strap indicating perfect timing (although I have absolutely NO carbon deposite ring at the bottom base of the porculian).
The only thing I can think of is that is it hot as hell here (Phoenix AZ, about 106 today, averageing 3000ft altitude), with a bit more humidity than usual. Both conditions add to thin air, meaning it is easy to "get rich quick". As a matter of fact, I performed a "correction factor" found here:
http://www.motocross.com/motoprof/moto/mcy...01/carb101.html
And it seems like for my riding conditions, if I wanted to use a 175 main, corrected, would be about a 165 main.
The only bummer I have about it is that my freind, with the exact same setup, runs a 175 main, with no problems, And I see most ppl have at least 180 on here (even recommended for jetting with my setup).
Any information you might have will be helpful. (For example,anyone else running a smaller jet setting with NP?)
I am concerned about being too lean, but what can I say, it runs perfect now. Besides, going up or down a couple of jet sizes should put your quad in danger of detonation that soon, would it?
Thanks in advance.
It is a dynojet kit, so please include what type of hardware you are using too.
Pepto :cool: