1982 atc200 fouling plugs

[3wheelerfan1991]

Hey there i have a 1982 atc200, 10.25:1 high compression piston with a 185 top end, everything else stock. So basically with a fresh plug this machine runs and drives great, doesn't smoke, great power, but if you leave it for a while (ex. overnight) and go to start it the plug gets wet and doesn't spark properly. With a fresh plug it starts first pull. I'm running a dr8es-l. The plug when pulled is black and has black resin on it. Ive swapped carbs, cleaned air filter, checked exhaust, moved needle clip but im lost on what this could be, if the motor is still hot it will start fine and run forever. Thanks to anyone that replies.

[Vealmonkey]

Sounds like the idle circuit needs re-jetted.

[3wheelerfan1991]

Sounds like the idle circuit needs re-jetted.
Thanks for the reply, I've tried different jets, carbs everything with no help. I even pulled the carb off my 200e, all this did was give more power but didn't help the issue.

[tri again]

Thanks for the reply, I've tried different jets, carbs everything with no help. I even pulled the carb off my 200e, all this did was give more power but didn't help the issue.

'doesn't spark correctly"?
you mean doesn't fire or bad spark?
I've saved lots of heartache by nipping the last tiny bit off the plug wire so the cap has fresh copper to bite into.
Fast and free and I'd check for spark with just the wire and no cap and then with a plug.
If that doesn't do it, search key for "no spark" and you'll get tons of info in one click.
I even read the stuff that isN'T for my machine.
Generally all connections and grounds, cheap volt meter to ohm the stator and other components.
Can you click on
service manual
?
It has all the tests and values.

Will it start with start fluid? when it's cold?
It's either fuel or spark and hopefully not both but with that carb swap doing the same thing, maybe spark or advance mech under the cover that says 'cdi'.

Please let us know what you find.

[barnett468]

with a fresh plug this machine runs and drives great, doesn't smoke,

if you leave it for a while (ex. overnight) and go to start it the plug gets wet and doesn't spark properly. With a fresh plug it starts first pull. I'm running a dr8es-l.

The plug when pulled is black and has black resin on it. Ive swapped carbs, cleaned air filter, checked exhaust, moved needle clip but im lost on what this could be, if the motor is still hot it will start fine and run forever. Thanks to anyone that replies.


What you are saying makes no sense to me unless gas is leaking into the cylinder causing it to flood. It would be unlikely [but possible] that this would happen with two different carbs though.

Based on my interpretation of your plugs condition, your engine is burning oil, however, it might also be running rich.

Burnt oil on a plug appears black and moist/gooey. Too rich is dry powdery black.

Are you turning the gas valve off on the tank when not using the vehicle?

If you ARE turning off the gas, you can disconnect the fuel line when done riding and either plug it ir put the open end in a glass to see if the valve leaks in the off position then reconnect it and see if it starts.


What is your elevation, air temp and EXACT starting technique with the plug that is left on overnight and the new plug you replace it with when it doesn’t start?

Is your carb orig?

Is your eng/exhaust modified?

Do you know the jet sizes?

What color is the spark, yellow or pale blue?

How many hours of riding does it take to get this black "resin" on it?

[3wheelerfan1991]

Thanks for the replies. Currently I have to get my appendix removed, so I can't look at the machine but when you hold the plug to your hand And pull it's not very powerful feeling spark. Yes the gas is off. And I don't think it's carb because I've tried a few, swapped jets etc. also it was rebuilt and doesn't burn oil. I'm leaning towards spark, if that would be my problem