I have a 77 KZ400A 2 cylinder that I just got running after sitting for 10+ years. I cleaned the carbs, changed the oil, put a new battery in, removed the head and had it fixed, cleaned out the restrictions and collapsed baffles in the exhaust, put new spark plugs in, rebuilt the points, and fixed and rewrapped the electrical wiring. It was running fine up to about 4000 RPMs in neutral, then it seemed to run out of fuel and rev back down to 3000. In gear, it could do about 15-20 miles per hour. I have a tank full of premium with carb cleaner in it, and it didn't seem to help. At one point, I switched the petcock valve and it ran beautifully for about 10 seconds then started running horribly and fouled out the plugs. With the fuel switch on RES, it won't allow barely any fuel out but on ON it lets a lot of fuel through. It hasn't jumped time or lost spark. I was given a bucket of parts with the bike, and in it was a motorcycle fuel pump. As far as I know, the KZ400A does not take a fuel pump, but now I'm second guessing that. Do I pull the tank and clean it out, remove the petcock valve and check the screen? Does this bike have a petcock valve screen in it? Could the carbs be plugging up again? Or is it possible that it ACTUALLY has a fuel pump? Thanks for your help guys!
-1980 KZ550C Viper Red, Black Fenders
