I would be grateful for any ideas. I have a 1989<br />Yamaha 55HP. The last three weekend outings the O\B ran well for an hour or so then misfires and eventually goes onto one cylinder. I have cleaned the carbs and checked the float heights, relpaced the spark plugs but still the symptoms are the same.The coils and CDI unit check out ok<br />in accordance with the wksp manual. Could they be breaking down when they get hot? Or could it be something else I may have over looked. Each time it runs OK for an hour.Thanks to all.
