my 77 kz750 was running fine then the next day was only running on 1 cyl. and was really hard to start to the point i couldnt get it to start so i thought it was the coil. i touched the coil and it was a lil warm but not hot. then i left it for a day went back to it and it fired on one cyl again so i swapped plugs from side to side and the other cyl was running. i put a new plug in it and runs like a top full of power. i took the bike to get safetied and it ran fine after the safety i parked and and went back to it at night and it was running on one cyl again. what gives? should i try and replace the other plug the plugs were like only a a few weeks old? could it be a bad coil but the bike only has one coil with two plug wires and way to check it?

 

What did the plugs look like?

 

one was clean a lil wet cus it wasn't firing but they look brand new. the other plug looked brand new but a lil bit of black carbon on it but it was the plug that was working.

 

Not sure but since you swapped the plugs and the other cyl fired, maybe you just are not getting enough umph from the coil?

 

yeah maybe, i'm gonna order an after market coil and see what happends and i'll keep you guys posted. thanks for the help

 

found the problem carb running rich on right cyl and plug get to wet to fire sometimes after sitting over night. replace with dry plug runs fine so until i get the carbs tuned i'll just have to rotate plugs everytime right cylinder won't fire. i keep a dry plug under my seat and when i switch it i put the wet plug under my seat after i blow it off and in light an hour or two it becomes a dry plug. so it will be ok until i get the carbs looked at professionally

 

hahaha, a pain in the ****. At least you found the culprit. I soak mine in MEK

 

yeah it is a pain at least i found the problem i was just about going to order a new coil that was gonna cost me like $159cdn