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Discussion Starter #1
Hello gang!

Keeping in mind what little I know about carbs, I'm thinking of rejetting my bike based on my altitude.
I am outside of Denver, so really nothing around here under 5,000 ft. My house is at 6,000 and most rides in Colorado take you further into the mountains up to 10,000+ feet at times.
My bike has developed a couple of noticeable hesitations, mostly at high throttle applications. The effect is slight, but still there here around the house, but gets more pronounced as you go higher. When calling for say 75% throttle or more you simply get a couple of hesitations as RPMs climb through the range, mainly at about 7K RPM, and then again at 10K.

Most all of the signs I am seeing say the bike runs too rich: MPG is a little bit low, in the 45 MPG range. The aforementioned hesitations. I changed plugs when I bought the bike and the old plugs have a pretty good black deposit ring around the insulator from the threads down. The bike has the stock 130 main jet in it and I assume the stock pilot jet as well.

So far I have broken down the carbs and cleaned them, even though to be honest they were extremely clean to begin with. The pilot jets and main jets are completely clean and clear. I have set the idle mixture screws at 2.5 turns out.

My question is what to try next?
I know FOG's airbox mod is supposed to lean out the top end a bit, but I'm not sure if it's enough. Based on my altitude I should have a correction of around 8% to start with, so maybe I should drop in a 120 main jet instead? Or both?
Also, I want some clarification on the idle mixture screw. Backing the screw out is actually richening the mixture, yes? I originally thought that it was leaning it out.

All thoughts are appreciated. I know a few of you are in the Rockies region, anyone see any similar problems?
Thanks so much for all your help!
 

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Knightslugger said:
use smaller jets.

up where the air is thin, you need less fuel for less air.
It's more less oxygen in the air(hence thinner). But ya. Less O=less fuel. I'm sure you knew that though and were just using laymans terms as pretty much everyone does anyways.
 

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ya, setting the pilot screw out is richer

maybe try 2 turns out or even 1.5 (which is what my bike had stock and ran fine)
i'd do that and the airbox mod and go from there (although i havent done the airbox mod on mine but i did change the exhaust)
 

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bhd1223 said:
Knightslugger said:
use smaller jets.

up where the air is thin, you need less fuel for less air.
It's more less oxygen in the air(hence thinner). But ya. Less O=less fuel. I'm sure you knew that though and were just using laymans terms as pretty much everyone does anyways.
::)
 

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Knightslugger said:
bhd1223 said:
Knightslugger said:
use smaller jets.

up where the air is thin, you need less fuel for less air.
It's more less oxygen in the air(hence thinner). But ya. Less O=less fuel. I'm sure you knew that though and were just using laymans terms as pretty much everyone does anyways.
::)
;) ;D
 
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