Jetting for different elevations...

[RiPPiNiTuP7]

As you get higher (elevation), what do you need to do to your jetting? Richer or leaner? Also, is there like a rule of thumb for how many feet high before you need to touch your jetting? Thanks in advance.

[Doibugu2]

The threashold that the Dyno jet uses is 3000, depending if your above or below. But you still may have to fine tune.

But the more you go up in elevation the leaner your quad will run. Which means you have to run a larger main.

As you go higher in elevation air " thins " out that's why it's harder to breath ontop of a mountain....so when you go up your jetting richens so you must lean it out accordingly...if your bike is running good where you are at you can usually go up another 2000 feet above where your at before a rejet...also other things taken into consideration like humidity and such

[Sparks425Ex]

Originally posted by WHiTeZ929RR
As you go higher in elevation air " thins " out that's why it's harder to breath ontop of a mountain....so when you go up your jetting richens so you must lean it out accordingly...if your bike is running good where you are at you can usually go up another 2000 feet above where your at before a rejet...also other things taken into consideration like humidity and such

It is just the oppisite.

The higher you go the leaner your quad is jetted. The higher you go on a mountan the less air there is. Meaning the less air that can get into your engine. So you must richen your jets. So that the Air to Fuel Mixture gets richer.

[Doibugu2]

Isn't that what I already said?

J/P:confused:

[jchevy]

the higher you go the richer you run. SO if your bike is running perfect at sea level and then you move to the top of a mountain at 12,000 feet your bike will be running rich, not lean.

If you are getting less air into the motor the less fuel you need to run.

yea the higher u go the richer it is. i noticed that my quad runs fine where i ride at exactly sea level to 10ft above then when i go to jack front which i believe is 3000+ feet i noticed the quad bogs a little from being rich.

[Steve-o 400EX]

The higher you go the richer the mix gets so u have to lean it out, but it is a touchy thing, only play with it if you notice a difference.

quote:
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Originally posted by WHiTeZ929RR
As you go higher in elevation air " thins " out that's why it's harder to breath ontop of a mountain....so when you go up your jetting richens so you must lean it out accordingly...if your bike is running good where you are at you can usually go up another 2000 feet above where your at before a rejet...also other things taken into consideration like humidity and such
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It is just the oppisite.

The higher you go the leaner your quad is jetted. The higher you go on a mountan the less air there is. Meaning the less air that can get into your engine. So you must richen your jets. So that the Air to Fuel Mixture gets richer.



Told ya...LOL

[jchevy]

If there is less air why would you want MORE gas?

Less air means you need less fuel.

Example:
Lets say you have a 170 main and you ride at sea level. On a WOT run you have just the right amount of gas. Plug is a nice tan color

Now you take your bike to a high elevation where the air is thin and you make a WOT run. When you have less air but the same amount of gas it will make you run rich. SO...you put a smaller main jet in and make another run. You are now feeding the motor less gas and less air and you are back to a nice tan colored plug again.


Please explain the logic behind running larger jets at high elevations. Adding more fuel when there is less air makes no sense at all. Its like going down a jet size when you take your airbox lid off.

[Team Outlaw #34]

lol people are just saying different versions....

THE HIGHER YOU GET....YOU GO DOWN IN SIZE OF JETS!!!!

Originally posted by Team Outlaw #34
lol people are just saying different versions....

THE HIGHER YOU GET....YOU GO DOWN IN SIZE OF JETS!!!!

yep

[Steve-o 400EX]

Originally posted by Team Outlaw #34
lol people are just saying different versions....

THE HIGHER YOU GET....YOU GO DOWN IN SIZE OF JETS!!!!

Yea what he said, the only way to really find out is experience the altitude change and see what happens with different jets.

THIS IS MY 200th POST. SWEET!!!!!:blah :blah :blah :blah

[0240099r1]

i guess i will add my .02 cents worth also the higher you go the richer your bike will run or any engine for that matter ........