Only firing on 1 cylinder

[warrenlevihursh]

I just got another XS, this time already built! I got it running good. Then I decided to move the coil and capacitor under the seat and clean up some wiring. It is now really hard to start and when it does, only fires on the left cylinder. Bike is simplified wiring and kick only. PAMCO/PMA. I'm leaning towards the pamco rotor being bad.

I swapped coils, plug wires, new plugs, no changes.

2 into 1 carb, spraying ether into the right cyclinder was no change.

Obviously it was good until I rewired things, but everything is so simple, I know it's all correct.

Can anyone give me any pointers?

 

[5twins]

A dual output coil fires both plugs at once, every time. If one plug has spark, they both should. Either both fire or both don't. If only one fires, the issue is usually with the plug, plug cap, or plug wire on the cylinder that isn't firing. So, my 1st check would be to swap the wires side to side at the plugs to see if the dead cylinder changes sides. If it does, that would point to a dead plug cap or plug wire on the non-firing side. If it doesn't, that would indicate an issue with the dead cylinder (compression, valves, fuel delivery), and also prove that the coil is firing both plugs.

 

[warrenlevihursh]

A dual output coil fires both plugs at once, every time. If one plug has spark, they both should. Either both fire or both don't. If only one fires, the issue is usually with the plug, plug cap, or plug wire on the cylinder that isn't firing. So, my 1st check would be to swap the wires side to side at the plugs to see if the dead cylinder changes sides. If it does, that would point to a dead plug cap or plug wire on the non-firing side. If it doesn't, that would indicate an issue with the dead cylinder (compression, valves, fuel delivery), and also prove that the coil is firing both plugs.

I've been thinking about everything today at work, and I am pretty sure it is a fuel issue and just coincidental that it started after rewiring the bike. I have 150 PSI in the dead cylinder. Nothing changed when I swappped the coil sides, or even coils and wires from another running bike. I'll take the carb off and go through it. It has to be the issue! Thanks for the reply.

 

[warrenlevihursh]

A dual output coil fires both plugs at once, every time. If one plug has spark, they both should. Either both fire or both don't. If only one fires, the issue is usually with the plug, plug cap, or plug wire on the cylinder that isn't firing. So, my 1st check would be to swap the wires side to side at the plugs to see if the dead cylinder changes sides. If it does, that would point to a dead plug cap or plug wire on the non-firing side. If it doesn't, that would indicate an issue with the dead cylinder (compression, valves, fuel delivery), and also prove that the coil is firing both plugs.

5twins, found a missing magnet on my pamco rotor which I believe would cause my issue. I had spark on both sides, just weak. Anyway. I know Pete retired, but I wanted to upgrade to the electronic advance without the blue box. Are they still available anywhere?