SO my mods as of now and for a while are, Pro flow kit with K&N, NO lid on my air box. and a white Bros exhaust. Jetting is STOCK took the bike camping/trail riding 9000 ft above sea level (FASL) I thought it was running OK until I rode some other guys BONE STOCK raptor just jetted for Higher altitude and it ROCKED mine! it ran wayyy better and was wayyyy faster. then I rode some other guys STOCK honda 400ex, re jetted for altitude and That ran even 10 times better than mine. so this is obviously a jetting issue. Heres the Kicker. everyone always says ******(read the Plug)****** however the plug looked PERFECT exactly the way it should have looked. if it was jetted properly, not white, not burnt, not gunked up... we also went up to 12,500 FASL and I had to keep the throttle reving high just so it wouldnt stall. I CAN NOT BE GETTING WAXXED BY A 400EX!
who Has the Ideal solution here? Please remember I am never lower than 5000 FASL and might often be 5000 higher.

 

If your jetting is off that bad your plug CAN NOT look good.

 

Here is one of the best jetting articles I have seen. It might help you resolve your problem. I never run higher than 3000 feet so I don't know much about jetting for altitude. Hope this article helps.

~HoundDog

 

you should be around 150/155 with those mods, at least I think that's what I ran here in Albuquerque which is just over 5000 ft, when I was only piped and K&N filter no air box. At these altitudes you should install a degree key or mor the plate or something. Your plugs can look great but youstill may not be getting a good flow of air and fuel, turn you a/f screws out to about 2 1/2 , and you really need to change jets from stock. I would jump down 2 sizes in jets for anything above 7000 ft

 

I will try to post a pic of the plug sometime this afternoon

 

Reading the plug is deceptive to a rookie... Your plug may look decent (tan to brown in color) if your lean in the midrange but rich on the top or, any other combo.

Keep in mind that you spend 90 percent of your time in the 1/4 to 3/4 throttle range and, that is the needle. Being lean in the midrange is the worse possible place to be off... More problems happen from lean midrange than any other jetting issues! Jet up! and, lower your clip one to get more air and, gas into that thing! ASAP!

 

and very good advice Capt. I forgot to mention the needles. I would invest in a dyno jet kit only about $60.00 and worth the money for our altitude this kit works very well.. Good luck

 

yeah that's exactly what would happen, I would get a good start but with more throttle it would appear to bog down then would pick up a little more through the top end. so then going 150/155 should be a goiod idea you think for 5000 + feet?

 

yes with your set up I would start there, you might be able to go more or you but I would start there and see how your bike runs. I usually leave off all the plastic and just bolt the tank down, and do some test runs to determine if I need to go more up or down, you will need to try going up and down just to be sure. All bike are a little different, your pipes flow different than mine so just take your time and play around till it's right on.

 

I am at 100 ft agl, and just got done testing my 170/175 dynojet kit, no lid, w/needles on 4th clip and it runs awesome....night/day difference from 148/150

i am happy