That was a common problem for the carbed Sammies. You need a vent tube to fix it. Here is an article that shows how to fix it in about 5 minutes.
Vent Tube
{taken from the article}
Carbureted Samurais are known to exhibit a “hesitation,” “bogging down,” or “flat spot” during acceleration. The problem may be exhibited in any or all gears. In the Samurai, the problem appeared as a distinct lack of power at some points in the acceleration curve. If you’ve got a carbureted Samurai (using the factory Hitachi carburetor) this fix is definitely worth a try. It improved the Samurai’s performance significantly.
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Linear Mode
