4-wheeler help

[Bucksaw]

To all the TBHers who are 4-wheeler mechanics. I have a 220 Bayou that is running funny, and Im out of ideas on how to fix it. It starts fine, idles fine, and drives fine under light throttle or full throttle. Under mild throttle though, it pops and sputters, and emits a little smoke out the tailpipe. I have tried adjusting the air/fuel needle, checked the timing, checked the valve lash, removed the air filter, drained the fuel lines and ran it dry before being filled with fresh gas, and none of it affected the way it was running. Im stumped. Any suggestions?
Again, it will putt around under light throttle, and run all out at full throttle, but it wont run right in between.

[sailor]

fuel filter perhaps?.....or did [I] miss something?

[sailor]

BTW-Love your avatar.........I want one

[hellbndr23]

When it starts to sputter pull the choke lever. Choke circuit on these carbs actual opens an extra fuel passage. It's a real quick way to see if your running too lean.

[Bucksaw]

fuel filter perhaps?.....or did [I] miss something?

Fuel filter is good. Its an aftermarket inline filter because these models didn't come with one from the factory.

BTW-Love your avatar.........I want one

Thanks. Got a couple more like it on the bench just waiting to be turned into knives. One from the same sawmill blade as the one pictured, and the other from an old farriers rasp. Feel free to PM me for more info.

When it starts to sputter pull the choke lever. Choke circuit on these carbs actual opens an extra fuel passage. It's a real quick way to see if your running too lean.

I will try that again, but I don't think it worked last time. To be honest, I cant remember what it did, if I tried it. However, The plug keeps getting black and sooty, which is a rich mixture, right? This doesn't seem to change no matter how I adjust the air/fuel needle. Am I adjusting the right part?

[twistedmidnite]

Pull the bowl off and make sure the float is sitting level. Sounds like it may be loading up a little

[trophyhunter01]

I had similar issues and replaced the needle and float fixed it right up.

[Bucksaw]

Pull the bowl off and make sure the float is sitting level. Sounds like it may be loading up a little

Explain, "loading up" for me. Sorry, but the only mechanical experience I have with small engines is changing oil and plugs on my mower, and basic assembly of this bike when I was rebuilding it. Im not up to snuff on any technical slang.

I had similar issues and replaced the needle and float fixed it right up.

Replaced the float needle, or the needle in the throttle gate?

[raceruss2003]

I was going to suggest jetting issues as well.

Did this only start after the weather cooled down or has this been happening for a while? Did you put on a new exhaust or anything like that?

If it was fine and suddenly made a change out of the blue, I would pull the carb and hose down the inside and out with carb cleaner.

Loading up is a term used for flooding itself out.

Here are a couple quick articles that might help you out. I wouldn't recommend buying a whole jet kit, you can buy individual jets from your local dealer for a fraction of the cost.

http://www.motosport.com/blog/a-simple-guide-to-jetting-your-carb

http://www.thejunkmanadv.com/motorcycle-carburetor-jetting.html

[trophyhunter01]

Needle valve assembly, order the part and a new float for the bowl. Those things can look good but not function correctly, with a bowl gasket had about $40 in parts.

[bowfishin fool]

They make a whole carb rebuild kit for that bike thats inexpensive... I went through a many of them as a child.

all the 220's and newer 250 bayou models should have the same parts

[MJQ90]

I was going to suggest jetting issues as well.

Did this only start after the weather cooled down or has this been happening for a while? Did you put on a new exhaust or anything like that?

If it was fine and suddenly made a change out of the blue, I would pull the carb and hose down the inside and out with carb cleaner.

X2 pull it and clean it!

[twistedmidnite]

Loading up is flooding like racer said. Have you had the carb apart? If you haven't I'd take it apart and clean the needle and seat and the jets. May have trash in them. Get a can of carb cleaner and a blower nozle on your air compressor. Your carb may not need a gasket set some of them are o ring sealed

[easeup]

x3

[Bucksaw]

I have cleaned the carb at least 3 times. Took it all apart and dipped it 3 different times, for about 2 hours each time. It was super gummed up when I got it, and took that much time in the dip to get it cleaned completely. I will check the float settings and see if that helps. IF not, I guess its gonna get another cleaning.