Beloved 1984 Trac Clipper still has no power

Mark Kinsler /
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Hokay. I'm learning the evil ways of the Encarwi carburetor float. In an unsuccessful effort to make a new float I had the old one out of the carburetor for about two days. So for recreation I re-adjusted the float level and after a few tries at it, eureka: the bike ran splendidly: right up the test hill, happy as it's ever been. I took a fast trip to the grocery store to celebrate, hooray, on to the next project.

Today, a day or so later, I started the bike and it was unhappy. It barely moved, and the spark plug was full of velvety black soot. I fooled with the carburetor float level some more, but my heart isn't in it: apparently the float dries out promptly when removed from the carburetor and then takes a few hours to soak up all the gasoline and sink once again, thus making the fuel/air mix far too rich.

So I've summoned up Myron's Mopeds to ask about their $25.00 replacement float, pouring out my heart in the requested email. But right now I'm ready to try replacing that Encarwi carburetor, which was apparently designed to be the flattest possible device of its kind for purposes of styling.

I have in the garage the wreckage of a motorized bicycle which decided to go to heaven last October and tried to take me with it. The front fender of the ancient bike dropped off when I hit an improperly-graded manhole cover, caught on the tire, wrapped the fender braces around the tire, locked up the front wheel, and spilled me right over the handlebars. Broken collarbone, badly stretched nerves, and a broken #2 cervical vertebra--i.e., a broken neck. I have healed nicely on all counts.

The engine of that bike is in good shape and essentially brand-new. I'm wondering if the el-cheapo Chinese carburetor would work on the noble Trac Clipper. The engines are of identical displacement; only differing in that the Trac has a reed valve and the motorized bike engine is piston-ported.

So I extracted the motorized bike carb along with its attached twist-grip and cable and the little manifold that adapts its clamp mount to the motorbike engine. No, the Chinese carburetor won't fit where the Encarwi carb did--nothing would, I don't think--but it shouldn't be much of a machining challenge to make a longer manifold that would allow the carb to be placed maybe twelve inches away near the rear of the gear case, where there's plenty of room.

My doubts are as follows: will a long pipe between carburetor and reed valve/crankcase be a great problem? The Volkswagen Beetle used very long, thin manifold pipes to its four air-cooled cylinders, so apparently you can get away with this sort of thing at some level. And if the Chinese carburetor's jetting (unknown at the moment) allowed the Chinese engine to run well, which it did, should I be concerned with this if I mount the Chinese carburetor on the Trac?

The proposed carburetor pipe would run alongside the exhaust pipe, so it'd likely stay fairly warm. The Trac engineers seem to have been worried principally about the Encarwi carb overheating, which is why there's a thick heat block between carburetor and crankcase.

The carburetor seems to be of the 12mm caliber, which corresponds closely to 1/2" plumbing, so I'd likely use that.

Let me know the thoughts of experts here, and thank you.

Mark Kinsler

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