Spark problem. Pls help.

Posted by Muscle racer on Nov 30, 2011; 4:38pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/Spark-problem-Pls-help-tp3548877.html

Like most old 750s, mine has its shares of problems. Thanks to this site, I always fix them. Now I have another one. Everything was running fine, when the bike felt like it was losing power. Like it was running out of gas. I had a  similar problem before, but it was a bad ignition coil.

After riding, I felt that the first 3 pipes were hot but #4 wasn't. So i know it's not the coils. When I ride, I can see blue spark going from the plug boot to the engine block on #4. Is it a spark plug problem??? I replaced all 4 spark plugs with new ones 4 months ago. It turns on fine and runs fine above 45mph.

I hope it's an easy fix.  

Pls help.

Thanks guys