I have twin 1994 txrs 250 yamaha's carbureted engines. The left engine is surging at wot 500 rpms back and forth. I replaced all the fuel pumps and filters. Before I go through the carbs I noticed the clear bowl for the fuel filter on the engine is half full all the time. The fuel bowl on the right engine is full all the time. I am assuming that is contributing to the problem, some sort of fuel restriction. What should I start looking for? Should I start looking before the bowl or after the bowl for a restriction? What would cause the bowl not to stay full all the time?
