4,500 feet - need air?

[Mtnman44]

Bike is stock and i ride mostly at 4,500 ft with a lot of mountain and off road trips that will be 5,000 to 8,000.

I am assuming that I am probably running a little rich right now. How do I determine this for sure?

should I cut a hole in the airbox and see how it does? do I need to rejet also or will a little more air alone do the job?

[Jim Hale]

yes... cut the hole in the airbox... you'll notice a big difference. It will correct the sealevel stock jetting (I did it when I still had everything stock like you). You wil get even a bigger boost by installing the dynajet kit with the proper jets.

[motoinmoab]

Do the 3x3 mod and you'll be fine with stock jets. I'm at 4,500' and ride up to 10,000'. It's a little pigish above 9,000' but that's asking a lot of any bike.

[Mtnman44]

Ok, just got back from my first test ride after cutting the airbox hole. You all can tell me how much of this might be from the larger hole and how much might be all in my mind.

First, I noticed that the bike seemed to start right up when I hit the switch, no throttle needed at all. Normally, I have to give it some gas for a second, especially if it's been sitting for a while, like today.

Second, the sound "seems" different. I want to say it sounds smoother and deeper. Not Harley deep of course, just dirt bike deep. It also seems more consistent and smooth sounding-more of a constant buzz vs. berfore which was more of a thump thump thump sound. not really, but thats the best way I can think to describe it. i hope I am making some sense.

Third, I did not really notice any more "get up and go" power or speed. It seemed about the same as before, only smoother sounding as described.

Fourth, when I really hit the throttle, revs sounded higher than before yet when cruising the revs seemed lower than before....?

[Jim Hale]

next you should think about dyno jetting and a better pipe. At our altitude you should be using a smaller jet. These are the settings as given to me by

Eddie.

You can get the kit at the Thumper Talk store or at Moto X in south Orem for around $65.

136 main jet

dj needle

3rd clip

dj slide spring

13mm float level (this is stock and doesn't need to change)

stock 22.5 pilot jet

2.5 turns fuel screw

These seetings are based on the Yosh pipe... the stock pipe is somewhat different.

[lonekazoo]

If one of you guys end up trying the new JD jet kit at 4500ft, be sure to let us know. I think I'll hold off buying the it (or the DJ kit) until Burned or someone else gets it figured out at various altitudes. Jetting seems like a black art to me ?

The 3x3 hole alone at 4500ft made a tremendous difference for me. It is a bit louder, but nothing annoying.