backfire in exhaust at idle or coast

[jerrymac]

i got a 79 xs1100 when i start it up and it runs for about 2 min i get a small backfire through the right side exhaust i new to these bikes and not real sure what it could be any ideas

[tarzan]

Pull the spark plugs on the cylinders that go to the right side #3&#4.See what they look like.That should narrow it down to a specific cylinder or maybe its both cylinders.
Are the plugs dry and black?Wet and black?White?Tan?
Let us know and if you can take a picture and post it so we can look.
Then it will be easier to help.
Rick
Oh,and welcome to the site.

[jerrymac]

when i first got it it was over filled with oil and the left cylinder was burning oil when i first started it i have since changed the oil the smoke went away but the rest of the plugs were a tan color if i pull the left wire off the bike will still run but have a slight miss same as with the 2nd one in and the inside one on the right side if i pull the last wire the bike will stall