I have a honda 78 cb400t and everything was running well and all of a sudden I´ll start it up and it will run fine up through all the gears then about a minute later it will loose power and the maxim speed is about 55 full out. Before this happens its will run right up to about 80 with no problem.This happens everytime it starts up , will run fine for a minute then loses power. I cleaned the carbs and made sure it was receiving gas. Is it the coil? or maybe the points? thanks cory