Motorcycle Repair: 1976 honda cb 750f, honda cb, afew hours

Question
Hello, I recently got this motorcycle ant it ran when I got it. I am now not getting any combustion. electric starter works but bike wont start. This is the second time this has happened. The first time it happened  I checked the plugs and they were fouled. checked each wire for spark and had spark. Then  connected cleaned plugs and checked each one for spark and one had no spark. changed all four plugs and she started right up. Road around town to different spots for afew hours and towards the latter part of the ride the bike would not idle. It started  to stall out so I kept giving it gas the rest of the red lights. Got home, next day tried to start it and got it started for a few seconds and that was it. Starter trying but no boom. Cleaned  fouled plugs and tried again and got backfire. Pretty sure it's the coil now. What do you think?

Answer
Victor, the problem is probably a fuel mixture that it too rich.  You didn't indicate if the fouling was oil or fuel but I'm guessing fuel.  It could be that float levels were too high or the air filters are too restricted. A coil failure doesn't react with that failure mode.

Regards
Rich