'77 cb750A
I've been fighting issues with the carbs every since I got the bike running after 20+ years in a barn. I knew I had to clean them when it ran crappy right out of the gate, so I did. That solved about 1/2 of the running bad.
It would idle OK but when I take off from a light it falls on its face and starts running on 3 cylinders. If I crank the throttle anyway the rpms come up and the fourth cylinder kicks in and it runs smooth. So If all I want to do it run 3/4 to WOT I'm set. Not real ridable to work and back.
Next I read for hours on this forum to learn what I could about the carbs. Now I feel like I know quite a bit about what effects what at what throttle possition, etc. Thanks eveyone who contributes here. After the third time through them I was 100% certain that the main jets were clear, the needles were set right and clean, the floats were set right and working. I was happy. Put them back on and again... fixed about 1/2 the issue. I had even pulled the petcock out of the tank and checked it.
Last night I'm working on it at 11:00pm (kinda pissed at the neighbors anyway) and happen to be standing in front of the bike looking down at the motor while flipping the throttle and to my surprise there are all kinds of sparks jumping all around way down in the hole by plug number 3. At an idle, no sparks. At 1/4 throttle and above sparks all over. when the RPMs come up they go away again. Now I know I need coils and wires but I just have to know if that's my "carb" issue. So I wrap the snot out of number 3 plug wire with electrical tape and go for a spin. It runs like a new bike. No miss at all.
Now the part I need help with. Where's the best place to get new coils & wires? It looks like I may have to take out a second mortgage to afford them.
Thanks
Dave