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adjusting the idle.


Unless you have the carb manual, don't mess with the idle screws on a Mikuni.

The problem sounds most like a vacuum leak somewhere under the throttle plate, like a cracked or loose vac hose or brake booster hose. You get a lean out with that, too, which heats up the carbon deposits in the combustion chamber to DAMN HOT, like hot enough to act as a glow plug and keep the engine dieseling. Look for leakies with a piece of hose in your ear. You'll hear the whistle at the leak.

IIRC, the fast idle thing has a vac control, too, in the dash pot on the back dside of the carb.



Thank you! So my next order of business is to fire up the Raider, grab some vacuum hose, jam one end in my ear and start poking around with the other?

I'm pretty carb-dumb: my last carb'd vehicle was a 1991 Jeep Grand Wagoneer, and one performed delicate adjustments on it with a 6-lb. sledgehammer. Something tells me the Mikuni wouldn't take kindly to that treatment.

When you say "under the throttle plate," do you mean *inside* the body of the carb, or somewhere around the base? Again, I have the junker that I'm using for a model, but it doesn't have any vacuum lines on it. I suppose I could track where the ports are and go from there, right?

Thanks for the help!

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87 Dodge Raider
2.6 5 spd stock
197xxx miles (gulp!)