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Carb tuning, 2006 600 RMK

Dogmeat

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Ok, I have two identical sleds ... 2006 600 RMK's.

I have them both set up like this:

270 main jet
55 pilot
0.9 air jet
Needle @ 2nd clip from the top with the spacer inserts installed

One sled I have 1 full turn out on the air screw, one sled I have 1/2 a turn out on the air screw.

They are clutched identically, 54g weights, blk/red secondary spring, stock helix, stock green(?) primary spring.

Both sleds have brand new plugs, good fuel, etc.

Sled that is 1/2 a turn out on the air screw seems to cut out right off idle at low RPM, sled that is 1 turn out on the air screw seems to sing right along through the entire RPM range. Sled that is 1/2 a turn out does just fine at higher RPM ranges though.

My question is, can the air screw adjustment cause this cutting out condition? Or is the cutting out probably related more to an ignition issue?

I'm honestly not familiar with the 2 stroke carbs, I've messed with plenty of 4-stroke dirt bike carbs, but I'm not sure what the air screw adjustment does on the 2 stroke carbs.
 

MARV1

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Yes, causing a slight lean condition. And wowzers, 55 pilots. I run 40's on mine and I think 1.5 turns out and no more loading up at idle and much better fuel economy...
 

Dogmeat

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Yes, causing a slight lean condition. And wowzers, 55 pilots. I run 40's on mine and I think 1.5 turns out and no more loading up at idle and much better fuel economy...

These are being set up for 8,000 + feet, you usually want a richer pilot at higher elevation is what I've always understood.
 

Dogmeat

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Ok, on the 2-stroke carbs does opening that air screw adjustment lean it out or richen it up? It should lean it out the more you open the screw up right?
 

Dogmeat

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That makes more sense.

I think 2 turns out will be the sweet spot, Im gonna go give that a try right now
 

Dogmeat

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Just outta curiosity, what are the "new" factory recommended settings for this sled? I've been screwing with these things for 2 days and I can't tune this low end bog out of them right now.

I have them set up with a 0.9 or a 0.6 air screw depending on the sled I've tried the fuel screw from 1/2 a turn to 2 1/2 turns out, 50 pilots, 55 pilots, you name it and it just stumbles like crazy off idle ...

Can bad fuel cause that as well? Runs great from about 1/3 to full throttle.
 

Dogmeat

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Have you tried adusting the needle? I've had to do that on 3 or 4 600's now.

I have, but only the first two clips ...

I haven't gone any richer than the 2nd ... but if I go from a 50 to a 55 pilot and keep the needle on the 1st clip, wouldn't that be the same effect?

What settings are you running for air jet / fuel screw / pilot jets?
 
D

dotter

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stumble

My 07 600 rmk had a stumble last year, started in bighorns, pulled all the jets, mains, pilots, pilot airjets fuel lines, blew out carbs and sprayed with carb cleaner. That worked!!! Agree with Marv try 40 or 45 pilots, maybe .6 or.7 paj, good luck PS it doesnt have an air screw, the white knob is the fuel screw, dont go less than 1/2 in, out more fuel, good luck Marv whats a wowzer??? :)
 
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