Made some changes to the bike

[IDAHOSPUD]

Got a 09 300ec, really like the bike. But i made some changes today, and it improved, at least for me. I have been running 13tooth front, 50 rear, and it was ok, but i always felt it was lacking in the grunt department, so i put a 52 Ironman on it, wow big difference, i can tractor if i need to, and it turned 2nd and 3rd into the perfect running gears. Very happy. I also changed my main jet as i have been hitting 6000-9000 feet and high temps this summer in the mountains, went from a 170 to a 165 main to a 162, much cleaner and has some top end now. Good changes, it also improved gas mileage. with stock tank, 170 jetting, it would go 50 and 6 miles on reserve. I hit reserve today at 62 miles. That helps, as i have been considering a desert tank. don't think i need to now.
I just could not be happier on the gasser on the tight, technical trails of Idaho.

 

[prentice]

same experience as yours with jetting changes at that elevation

Last September I had the same experience with main jet changes at those same 6000 to 9000 foot Idaho elevations, in the Stanley area. On a 2004 GG 300, started with a 172 main, and after trying a 170, a 168, ended up likewise with a 162. Works great at wot at those high elevations on my bike. Also went from a 40 pilot down to a 38, then found a 35 worked best. All with a #7 slide and, I think, a DDK or DDJ needle (I forget which one is in this bike), top clip (leanest). Bike ran very well. Agree with you on the 52 tooth rear sprocket as well.

What did you end up with as far as pilot jet size, needle, and clip position at those high elevations?

 

[IDAHOSPUD]

38 pilot right now and using JD red middle clip. There still may be room for some tweaking here on the needle, and pilot. I think, and this is just a theory, that the bike take leaner settings across the board because it is so dry here. The chart in the manual is pretty close but the low humidity does not factor in very well. So running better, at least with the heat we have been having.

 

[desertgasser300]

I have a 38 pilot 2nd clip on a CEK needle and 168 main.

Still have a bog off idle and hard to keep idling. I'm riding at 7000 to 9000ft. Was concerned about going leaner on the pilot to get a clean idle. Mid to top rips and has great tractorability.

I am surprised the pilot could be leaner. Is this common for a 300 to run this lean? It is very dry here also.

Very dry where I live. Moist where I am riding!

 

[twowheels]

I think, and this is just a theory, that the bike take leaner settings across the board because it is so dry here.

Hmmm ... if it's dry there is less moisture in the air, so more oxygen, so you should need more gas to achieve the same mixture .... that would be richer brass I would think. Leaner because of elevation I could be convinced of ...

 

[Nick]

I know this goes against the grain but go to a bigger pilot jet in the altitude. at high altitudes the engine has a hard time drawing fuel at low rpm so the bigger pilot jet helps. Kinda like a 125 has bigger jets than a 250 or 500 as it cant draw the fuel.