What would cause a 4 wheeler to excessively foul plugs

[ted_kennedys_liver]

I have an 06 Kawasaki Bayou 250 that fouls plugs excessively - plugs are very black. I replaced the carb on it and it still does the same thing. Would it be the coil and/or regulator/rectifier? That is about all I can think of at this point. Thank you in advance for your help.

[Shinesintx]

I have an 06 Kawasaki Bayou 250 that fouls plugs excessively - plugs are very black. I replaced the carb on it and it still does the same thing. Would it be the coil and/or regulator/rectifier? That is about all I can think of at this point. Thank you in advance for your help.

The reg/rec just charges the batteries.

I had a KX 250 that would foul the plugs if I putt putted around on it. Didn't have those issues when I rode it hard.

Lean or too rich? Not sure which fouls plugs.

[ted_kennedys_liver]

The reg/rec just charges the batteries.

I had a KX 250 that would foul the plugs if I putt putted around on it. Didn't have those issues when I rode it hard.

Lean or too rich? Not sure which fouls plugs.

Way too rich. Like its not getting enough fire from the plugs.

[lovemylegacy]

Ethanol or water

[jruss]

Gas these days are awful on small engine carbs. I would clean the carb run some sea foam through it and start using supreme in it.

[Coon]

Are you certain it is gas fouling and not oil fouling? It could be oil blowing by the rings and fouling the plug. Just a thought...
D

[ted_kennedys_liver]

I inherited the 4 wheeler from my uncle. He had the same problem with it since the day he got it back in 06. Dealership told him it was the carb. He didnt want to spend the money so he just kept changing plugs. Last year when he gave it to me I put a new carb on it and it is still doing the same thing. I have run multiple tanks of gas through it. I run premium gas in it. I do "putt" around in it some but run it hard just as much.

[ted_kennedys_liver]

Are you certain it is gas fouling and not oil fouling? It could be oil blowing by the rings and fouling the plug. Just a thought...
D

I hope not but as black as the plugs are you may be on to something. The next plug it fouls I will look at it closer.

I assume there will be oil on the plug?

And if so I guess that means an engine rebuild????

[vanmedic]

Sounds like it running to rich, try taking the mixture screw clockwise 1/2 turn it should be between 2-2 1/2'' turns out from bottom to be correct but like said above the fuel you get now days just isn't good

[Shinesintx]

Sounds like it running to rich, try taking the mixture screw clockwise 1/2 turn it should be between 2-2 1/2'' turns out from bottom to be correct but like said above the fuel you get now days just isn't good

I'm fortunate to be able to run ethanol free in mine. Will not run anything else.

[vanmedic]

Seems that they bayou's I have repaired seem to run much better at about 1 1/2 to 1 3/4 turns from bottom. It is located on bottom of carb at the front you can access by loosing clamp from intake and pivot the carb to the side, it may have a brass cap covering screw if has not been adjusted in past, remove the brass plate and there is the screw.you can prob find a how to on youtube on this, very likely to be the problem if other suggestions don't pan out.

[kingranch]

Prolly has an excessive oil blow by the rings or leaky valve stem seal...
I assume it's four stroke

I would personally pull the head off and see what it looks like.
A new top end is cheap and easy to do if u have any mechanical knowledge

Carb fouled plugs usually wet with gas etc....
Oil fouled will be black and oily

[Swampa]

Prolly has an excessive oil blow by the rings or leaky valve stem seal...
I assume it's four stroke

I would personally pull the head off and see what it looks like.
A new top end is cheap and easy to do if u have any mechanical knowledge

Carb fouled plugs usually wet with gas etc....
Oil fouled will be black and oily

What the hell do you know?

thought you were in Missoura

[vanmedic]

I hope not but as black as the plugs are you may be on to something. The next plug it fouls I will look at it closer.

I assume there will be oil on the plug?

And if so I guess that means an engine rebuild????

Does it smoke after sitting a while? usually if you have weak rings or valve seals you will have a period of white smoke after intial startup and may clear up after warm up.This may not be true 100% of the time but more times than not this is the case, I would sure start out on the simple things JMO

[old killer]

A friend had a similar problem in the mountains. His battery terminals were loose and causing the engine to not fire speratically. This caused the plugs to foul.