84 honda 200m dry black plugs

[durrer17]

My honda 200m runs very well when im on it but whenever I check the plug it comes out with a dry black carbon layer on it. It still seems to run even when it is covered but I figure something isnt right! Once it is warmed up it idles very low or it just shuts off. I cleaned the carb and I think I have the mixture set right but Im not sure. What is the best way to set the mixture screw on the carb? I have been revving it up and trying to find the spot were it doesnt sputter when I hit the throttle. Any ideas what could be the problem?

[barnett468]

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ok, i would start by doing the following:

if the gas is old or yellow, change it.

check the float level

..................here's an example of it a little too high . . it should be just below the solid black line in your case.

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.................................................h ere's another and you can see the is level way too low.

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[barnett468]

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i would then check for vacuum leaks with flammable brake cleaner with the long nozzle and gently spray around the carb boot at the head and intake.

if all is well and your air filter is clean, i would install a new spark plug and go down 2 sizes on the main jet then ride it around for maybe 20 minutes if it runs ok then look at the plug.

[atc007]

There is a O ring under your intake manifold,against your head. Replace it. Even if it's still good. It's a 30 year old o ring that's been baked at engine temps that long . Then start playing w your jetting. 90% of these 200 carbs are simply worn out with no serviceable adjustments left in them. Body and slide,Worn out from the 30 years of vibrations. Some have had great success with the $20 china units, some have not. For the price? I say get one and test from there,if your current set up doesn't pan out.