I picked up a cheap 1999 Bayou 220. It started right up but had little power, it hardly moved in gear with full throttle. It also didn't idle and was loud.
When I got home I gave it oil change. There was 4-5 quarts of oil in it. It should have had 2. After putting the proper amount of oil in it, its power is back. However it still runs really rough, it still wont idle, and dies without throttle. I checked the timing and that's good. I cleaned the carb and put the gas screw back to the stock and I've messed with the air screw but I haven't had much luck.

It only starts if I'm feathering the gas. Then while riding it anything less than 1/2 throttle feels really choppy. With full throttle it actually feels ok but it's still really loud. After riding it for about 10 minutes I gave up for the night. The next day it didn't want to start, I took a look at the new spark plug and it's black. I'm pretty sure it would start with a clean plug.

Any ideas what's wrong? I'm sure running it with all that oil wasn't too good for it. Would that blow some kind of gasket or seal? Or any other ideas of what might be wrong?

Thanks

 

Check the choke is working properly and the air filter, it could be full of oil. If they are OK you will have to work on the carb again. Check the jets are standard. It looks like you may have to adjust the slow running jet. I never do, but someone may have altered yours. you could try dropping the main jet needle a bit.

 

I put a new spark plug in it yesterday and had it running for about 5 minutes before it blackened the plug and died. While it was running I noticed a steady flow of air coming out of the air intake. Do you know what could cause this? Tomorrow I will check the air filter and take the carb apart again. How do I check if the jets are standard? Thanks

 

Cam timing on quads is a bit "wild" so they do tend to spit air out before sucking it back through the carb. If the cam timing is right, only a worn cam can cause excessive spitting back.

Unless you have a shop manual with the numbers listed, the only way to know if your jets are standard is to buy a rebuild carb kit and check the numbers on old and new jets. I would check the choke, try running without an air filter, and adjust the main jet before going to the expense of a rebuild kit.

 

sounds to me like a jet is plugged and maybe the air/fuel screw might need adjusting.

there is a pilot jet with very small orifices. The main jet is easy to see if clean. the little carb circuits must be clean.

Not sure what you mean by gas screw. The air screws on my Concours are about 1.75-2 turns out from lightly seated and I would guess yours should be in the range 1.5-2.5.

If the screw is on the airbox side, it is an air screw. On the engine side it would be a fuel screw.

OEM jet sizes are here:
https://www.kawasakiepc.com/SystemSe...TOKEN=46077116

Carb cleaning tips are here:
http://faq.ninja250.org/wiki/Cleaning_the_carbs_2