Maybe someone can steer me in the right direction. Once in a while after a few days of not riding, the bike startsup and seems to run on three cylinders. Then as it warms up the last cylinder starts working. I had the carbs cleaned and still have the problem. I did have a bad spark plug on the right most cylinder and replaced it in early spring. Now it seems to act up again. I am not sure if it is a ignition coil problem or spark plug wire. Has anyone had a similar problem? Can someone recommend what to test? Would appreciate any help.

 

Try swapping the coils over and see if the problem moves to another cylinder...this will at least rule out the coils as the source.

 

Will try and let and see how it goes.Thanks for the tip