Motorcycle Repair: katana, bikebandit com, piston valve

Question
Hi. i just bought a 92 suzuki katana on craigslist. and im putting it back together. now after i start it after it runs for about 10 to 15 seconds its constantly leaks fuel out of the air box vent hose.  im not sure if maybe i have hoses wrong. or im also wondering if maybe because the fuel pedcock needs to be replaced. i put the old one back on just to see how it runs and am getting a new/used one tomorrow. the fuel that leaks looks like its coming out of carb num 2. what do you think could be the problem?

Answer
Hi Cody,
Compare the hose connections on the other carbs, if they have the same hoses they may be connected in the same manner. It sounds unlikely its the petcock, it sounds like the float or needle/seat is stuck or damaged and not shutting off the fuel properly in that carb. Your first action should be a service manual or at minimum a diagram of the carbs. You can find one here for the 600 Katana, if its a 750 you will have to navigate to it.

http://www.bikebandit.com/1992-suzuki-gsx600fn-katana/o/m6171#sch278773

The internal carb components are assembled with great precision, if you have them apart you will have to be VERY METICULOUS during reassembly!! They won't work properly if even small changes or omissions are made. The float height is critical for proper performance and keeping them from leaking/running over. Cleanliness and proper assembly are paramount. The air bleed screws setting is critical for low rpm operation, diaphragm/piston valve (slide) jet needle and needle jet for high rpm.
Regards,
Terry.