Air/Gas Mixture on Carborator

25124 Views 35 Replies 8 Participants Last post by marine, Dec 3, 2003

marine

Discussion Starter · Nov 18, 2003

I just called my local Dealer and he advised me to adjust the air screw on the carborator bowl to get rid of the sluggishness off the line. Told me that the EPA forces them to adjust the screw very lean. He said that its located in the front of the carborator and that adjusting it will greatly increase the "pep" of the bike when accelerating quickly. I am going to try and find this aadjustment when i get home. Any advise from you mechanical gods!

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Yellow650Rincon

· #2 · Nov 18, 2003

I have never heard of the idle mixture screw helping the off-the-line bog.

By the way, that screw is on the bottom of the carburetor. And the only screw on the carburetor bowl is the one to drain the fuel. My dealer suggested draining the bowl, because it may have had junk in it. It didn't help mine, but it might yours.

Metimbo

· #3 · Nov 19, 2003

I think he was talking about the "pilot screw" on the bottom of the carb. It is also referred to as the "Air Fuel Mixture Screw".
It is on the bottom of the carb, flat head screw, screwed in from the bottom. Pull off the side panel on the right side of the bike. Get a little flash light and shine on the bottom of carb. It is towards the front of the bike a little. Screw it in all the way, then back it out starting at 2 1/2 turns. Start bike, and let it warm up riding it stop and go for about 10 mins. Try and wheely, if it feels the same, back the screw out another 1/2 turn and try again. You really should'nt have to back the screw out any farther than 3 1/2 turns I wouldn't think.
That is how you adjust the pilot screw or air fuel mixture screw on the Rinny. This will effect idle and just off idle acceleration.
~Tim

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marine

Discussion Starter · #4 · Nov 19, 2003

Thank you so much tim!! And Yes, this is what I was refering to. I couldn't do it last night as there was a tornado that went through so not excatly good weather to ride around and test a carb setting LOL!

sparky

· #5 · Nov 20, 2003

Tim is correct...I havent really noticed much change when backing the screw out more than 3 full turns. Anything over 3 turns hasnt made any difference on mine....

marine

Discussion Starter · #6 · Nov 20, 2003

Q, How do I get to this screw. I looked last night at the thing and it appears to have alot of stuff on top of the carborator. Any direction on how to locate the screw. I guess worse case I was told there are only two screrws...one that works as a drain and the air/gas screw. I belive I will put nail polish on the screw and the carb. just incase I mess up the settings I can get it back where its supposed to be! LOL

Metimbo

· #7 · Nov 20, 2003

It is on the bottom of the carb, flat head screw, screwed in from the bottom. Pull off the side panel on the right side of the bike. Get a little flash light and shine on the bottom of carb. It is towards the front of the bike a little. Screw it in all the way, then back it out starting at 2 1/2 turns. Start bike, and let it warm up riding it stop and go for about 10 mins. Try and wheely, if it feels the same, back the screw out another 1/2 turn and try again. You really should'nt have to back the screw out any farther than 3 1/2 turns I wouldn't think. That is how you adjust the pilot screw or air fuel mixture screw on the Rinny. This will effect idle and just off idle acceleration. ~Tim

sparky

· #8 · Nov 20, 2003

Yep...its the ONLY screw that goes in from the BOTTOM. The drain screw in ON the bottom, but it goes in from the SIDE. The head of the mixture screw faces the ground and is the closest to the engine side of the carb on the bottom.

I have to use a little flat head screw driver tip from a cordless drill in my fingers to reach it.

If you start at 2 and 1/2 turns out like Tim said, you cant mess it up.

marine

Discussion Starter · #9 · Nov 20, 2003

Thanks guys!!! Its on tonight! I will post on here if it affected it or not. I am assuming that if tim can get 27" 589's off the ground while leaning over the front rack that I can get stock 25" tires way up!

sparky

· #10 · Nov 20, 2003

If you have stock tires on, you should be looking at the sky when you pin it...

...I have 26" Mudlites and mine comes up fine.

marine

Discussion Starter · #11 · Nov 20, 2003

Ok, I have the side of the bike off, but I cant see around all the black tubes? When you say right side is that facing the front or back of the ATV? does the screw have a black plastic thing on it? I found one of those..

marine

Discussion Starter · #12 · Nov 20, 2003

FIXED!!! at lest I think so, It was at about 3.25 turns out. I put it all way in then turned it 2.75 turns out. and VUWla! I can get the wheels off the ground and it doesnt bog down when i hammer the throttle wide open!! however, It didnt feel like the wheels were going that high! Maybe its just because I have under 200 miles and it wasnt fully warmed...it was dark and lots of traffic. I live in subdivision and the neibors didnt like me poping wheeles down the road and screeming up to 59 MPH...still my top end.

sparky

· #13 · Nov 21, 2003

Good....3.25 turns out is way to far with a stock machine...you may even be able to take it in to 2.5 turns out and be better.

I think the factory setting is about 2 and 3/8 turns out...I think.

marine

Discussion Starter · #14 · Nov 22, 2003

I will try the 2.5 turns today...its really nice out!! crazy for late November i am wearing shorts!!!

marine

Discussion Starter · #15 · Nov 22, 2003

Yeah, it works at 2.5 as well. running it as lean as possible is good for plug right?

Yellow650Rincon

· #16 · Nov 22, 2003

What do you guys mean on the right side of the quad? When the carburetor is mounted in, it would be on the left side. (The left side when sitting on the bike facing forward). The only screw on the right side is the drain for the carb bowl. The idle/air mixture screw is on the left side on the very bottom of the carburetor. Unless you guys are referring to the IDLE SPEED adjustment knob. Which is a black knob on the right hand side, which does connect to a screw on the carb.

Jason, running the quad lean is NOT good. It makes alot of heat and could possibly burn a hole in the piston or some other kind of damage. Check the plug, if it is hazed over with white film, it's too lean. What you want is an idle mixture, where the plug is a brown color. Black indicates a rich mixture. Running it rich is better than running it lean.

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marine

Discussion Starter · #17 · Nov 23, 2003

Ok, yes you are correct about the side its on the left. It took me a great deal of time to find but I did (after taking all the plastic off the right side LOL! I was wondering what that black plastic screw was connected via cable into the side of the carborator! LOL...Is 2.5 turns to little?? Its hard to tell the turns..crap I can barly see up in there. Luckly I have small hands and the pull start is movable!

Yellow650Rincon

· #18 · Nov 23, 2003

Yes, to get to it on the left side you have to remove the plastic. I had to use a stubby/shorty screwdriver to get to it. I was just trying to tweak it after I had the whole mod done. But trust me it is easier when you have the carburetor fliped over! lol

It's hard to get to due to the exhaust pipe being right below it. To tell how many turns you have done, look at the head of the screwdriver.

marine

Discussion Starter · #19 · Nov 24, 2003

Well, What i did was watch the flat part of the screwdriver while holding the flashlight still. When the screwdriver would reflect the light from the flashlight I knew I had gone 180 degrees. Of course we all know it takes 360 degrees. Therefore, every time I saw the light reflected 2 times it was 1 turn out. So i watched for the light to be reflected 5 times....therefore I had turned it out 2.5 times

dickmadison

· #20 · Nov 24, 2003

Did you remove the carb completely or just loosen the clamps enought to turn it over while it was still mounted? I tried to get to mine today and these fat hands can't do it from the right side. Is this the same way you got to the main jet to replace it? I removed the long clear pastic intake tube but was not sure how to get the left side plastic off without breaking something. I would like some help and maybe even pics. The screw I was trying to get to is just behind the black intake boot on the flange. Does this sound like the correct one. That is the only ne I can find other than the idle adjustment and bown drain. It really has a flat spot off of idle with the tube off. Seems to me, the little black snap on cover on top of the air intake tube is very restrictive. Then looking at the size of the header pipe and the small tail pipe, looks like the engine is very detuned as far as air in and air out. Thanks

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