I have a '86 Bayou and when I install a new spark plug and crank the engine the spark plugs fouls out in 30 seconds to 10 minutes. That seems to be the only problem with this atv and need some help determining what is the problem. Thanks

 

Chances are, the "enriching" or "choke" plunger is sticking in the rich position.

Unscrew the plastic cap connecting the "choke" cable to the carburetor. Withdraw the choke cable, spring, cable end and plunger.

The system may stick in the "choke" position if the probe on the plunger is bent or misaligned, not centered (if the plunger can't seat, it can't seal off the flow of raw gas into the carburetor); the probe can be bent when the platic cap is tightened when the probe is not seated; tightening the cap without the probe seated sometimes bends the probe. If this is the case, straighten the probe if you can or buy a new plunger.

If the probe seats properly, the choke cable's plastic cap fits up against the carburetor body threads with only slight resistance from the coil spring when the choke lever is in the "off" position.

Another possibility is a defective spring, whose job is to force the plunger probe into its hole in the carburetor when the choke lever is in the "off" position. Yet another possibility is the choke cable sticking in its sheath; not unheard of in a quad as old as yours, you must then clean and lubricate the cable. You can check this condition when you disconnect the cable from the carb; work the choke lever and observe whether the plunger moves in and out freely.

The choke cable cap is a mean part to reach; although it seems like lots of effort, you'll save youself LOTS of frustration if you remove your tank to inspect and work on this part.

Another possibility is too-rich setting on the "pilot" screw. The starting position is 2-1/8 turns out from the bottom. Along this line, the pilot screw and/or its seat could have been boogered from over-tightening; this event could result in an over-rich mixture at low- and mid-throttle.

In "Tech Tips," accessible from the ATV Connection home page, you may want to read the article on Keihin CV32K carburetor maintenance, if the possibilities above don't locate and solve your problem.

Tree Farmer

 

I second the comments made by Tree Farmer. Sounds like you have a more severe case of a problem that I had with a '92 model Honda TRX 300. It would foul plugs after about 4 to 6 hours of use. In this case, the tell-tale sign of rich mixture was poor idle performance. I had the carb rebuilt and now it runs and idles like a champ.

 

Hey, MikeyM! How about some feedback, man?

What's the story on your Bayou? Did the carb suggestions help?

I hope you're not fouling plugs from pumping oil past shot piston rings!

Please, let us know how you're making out.

Tree Farmer

 

Thanks for your suggestions, but I haven't tried anything yet. I haven't had time to work on it, but I should be working on it sometime mid-next week. I will let you know how it went, and as for the shot piston rings I have a bad feeling that that could be the problem. I just recently purchased it from my girl-friend's grandfather who took excellent care of it, I believe he asked a local shop and was told that that may be the problem. I hope for my empty wallet's sake that it's just the carb. Thanks

 

Thanks for all your suggestions. I cleaned the carb 3 times and it would sputter a bit and then die. So I took to be fixed and found out that there was water in the tank and it was also very dirty not to mention that the gas had been sitting in there for over five years. Now it runs and idles like a champ. Thanks

 

Glad to hear it Mike. Who said that you can't find such an old Kawasaki ATV that still runs like a champ.