Cylinders 3&4 not firing

[Guest]

I have a 79 gs850 with points ignition and cylinders 3&4 are not firing. I was wondering if anyone might know why. I'm not sure what all info you might need to help but I have spark at all plugs and fuel in all carbs but it's running only on cylinders 1&2. The two left (while on bike) pipes get hot while the two right pipes only get warm. If I spray starting fluid in carbs 3&4 there is no change. I have raw fuel coming out of the right side pipes. Thanks for any help

[Brendan W]

Take out the plugs and clean them. Refit the plugs and swap over the HT leads 1&4 , 2&3 and see what happens.

[phydeauxmutt]

Follow the spark plug wire from #4 to its coil. Continue on the other side to see which plug the other wire goes to. It should go to #1. If it goes to #2, swap the wires on #3 and #4.

If someone has replaced the plug caps on the wires and has not put the proper caps on, it will be easy to confuse which wire goes to which plug. The stock caps are different lengths, the inner ones are longer than the outer ones.