Posted by jason on April 01, 2001 at 19:22:49:
Ok here's the deal, I've worked on everything from solex to quadrajets, but this thing has me stumped. For those of you that know cycle carbs (this is my first)mabey you can help. A carb is a carb, right? First, I installed a jardine muffler, went from a 145 to a 155 main jet, removed the paper in the airfilter element and replaced with UNI green foam (oiled), drilled out the brass plug (check this, the air fuel screw was ALL the way IN. must not have been idling on the idle circut)and adj the carb. I'm now 1.75 turns out. The bike runs great!Plenty of power! No backfire when I shut it off. My problem (or annoyance) is when shifting, I get a little "pop" or backfire. This shouldn't be. My first thought was the pilot jet is too small. I went to the dealer and bought a 55 (stock is a 52.5) took the old one out last night and the new one is different. size and shape is the same, but the shaft has holes in it and the metering hole is in the threaded end instead of the seating end. Now this shouldn't make a difference unless fuel will leak past the threads. Now the dealer swears it's the proper one. It also fit the vn/vl carbs. With the new one in, the air fuel screw needs to be all the way shut for fastest idle? what the #*&@. Now I'm NOT willing to just "deal" with the "Popping", so if anybody can shead some lite on this I'd be really grateful.