Anyone own a Katana?
I was reading the "Tech Q&A" section in the February, 2004 issue of Rider Magazine and found a question about fouled plugs on a Katana. The bike in question is a 2002 600, but might apply to the 750 and other years.
The rider had dry black plugs, but the float level was correct, the jets were correct and tight, and the float needles and seats were perfect. With only 2,000 miles on the bike, he changed the plugs and they fouled again. What was the problem?
The Mikuni carbs on the Katana use plastic float needle seats that are pressed in with a sealing O-ring. The O-ring shrinks from heat allowing gas to bypass the needle, seat and float. It's not a gusher, but it allows excess gas to foul the plugs. So check those O-rings if you have this problem.