"Runs great at full throttle b
"Runs great at full throttle but idles rough and often dies. Ran great in May but started this problem this past weekend. I don't know anything about the Yamaha motor’s fuel system, but it acts like an idle jet has a restriction, maybe varnish. If that is a possibility, is there any additive like B12 Chemtool by Berryman that might be successful in cleaning the passage?"
"Runs great at full throttle but idles rough and often dies. Ran great in May but started this problem this past weekend. I don't know anything about the Yamaha motor’s fuel system, but it acts like an idle jet has a restriction, maybe varnish. If that is a possibility, is there any additive like B12 Chemtool by Berryman that might be successful in cleaning the passage?"