99Shawk

I've posted on similar issues a couple times trying to push a bit more out of my bike (I'm convinced she's not running at full potential) but a newer issue has come up.

I took her for a ride 2-up up Rist Canyon today (any NoCo folks on the forum that may be interested, they finally swept all the sand off the upper canyon) and mid to high up the canyon, I noticed that if I accelerated pretty good, it would stutter pretty bad, almost cut out. Also at the top of the canyon when I just let it idle, it was idling real low, around 700-800. I have the idle set to 1200 normally. My question is, is it the altitude? It has stock jetting from a Colorado dealer so it's jetted for the altitude, I know that much. The PO gutted the exhaust but did not rejet it. I was getting pretty gnarly lean surges around 3500-4000 rpm so I shimmed the needles an additional .027 on top of the existing washer to try to give it more fuel.

Also, no idea if this is related, but when I take the carbs off I notice that one fuel line has a lot more fuel in it than the other. Could this play into it at all?

I've done some searching on here and haven't found a whole lot that I could relate to my bike.

On top of it all (sorry for the barrage of questions) but it seems to be weak from 4k-7k...... That's probably calling for a larger main jet, right?

NZSpokes

Go to the Tech section and rear the jetting thread. But it sounds more like a vacuum leak or something along those lines. I would be pulling the carbs and giving them a clean out along with a good check.

2wheelsagain

Did you get fuel at an out of the way place. Sounds like a dodgy tank of fuel to me.

jerryh

Yeah run a fresh tank of fuel. Theres a chain of gas stations in knoxville that causes my bike to sputter and die. Mainly at or near idle

99Shawk

I gave the carbs a good cleaning last august when I bought it, stored with stabilizer, and cleaned them again when I shimmed the needles just for good measure (figured since I was in there might as well do it right) I've been using shell premium for the last 2 weeks. There is a team petroleum that sells 100% gasoline a few miles from me that I have yet to try, might give it a shot Monday when I have time to ride again and see how it goes.

Tofazfou

Don't know if this helps but, i can say for sure that when i ride here in California in the mountains, the air is thin so my bike either idles really low or it cuts off all together. But i don't have any other issues with acceleration and such when im high in the canyons. This is at about 4000+ ft altitude and higher.

One way to be sure of this is to simply check performance at the top of the mountain (high altitude) vs at the entrance (low altitude). If you bike runs normally at the bottom of the hill then runs worse at the top the YES, Altitude is your problem.