Well not it......It feels like a miss in the rear cylinder. Could the coil show a constent misfire? It idles rough but when you get on the throttle it pops and spits.

 

Bad gas maybe.

 

The seal between the carb and the intake is pretty rarely a problem. The seals between the heads and the intake go bad all the time. Get it idling and spray a little carb cleaner around the junction between the head and the intake runners. If the motor sound changes, you have a leak.

New plugs are useful at times, but new wires almost never cure a problem. If you can touch the wire with the bike running without being thrown across the shop, the wire is fine (super cheap plug wire tester).

 

Is there a way to check the coil to see if it is bad?

 

Sounds like you've got a hot enough spark to run it.

Backfiring is typically a sign of bad timing. But it could also be time to rebuild the carb.


You have to disconnect the coil and can test Primary and Secondary sides with an Ohm Meter. Manual will tell you the range.

I heated my coil (blow dryer) and the primary resistance changed under heated conditions and it showed beyond the tolerance. However that still is not the final issue with my situation.

Still looking for Gremlins ...lol

 

I agree with the good doctor, it is either an intake leak or some trash in the carburetor.

Pull the carb and clean it out good, and check all intake parts.

Backfiring is a symptom of lean mixture, as is rough running when cold and needing the enrichner.

 

The rear cyclinder is the only problem....How do you know your timing is corect? Can you adjust it without tearing it down?

 

Alright....I cleaned the cab with carb cleaner and I also tried sraying carb cleaner into the manifold area with no change. I took off the air claener and noticed when it backfires it shoots a flame in the carb. Also at idle it is puffing smoke out of the rear cylinder pipe.
Could it be possible that the coil could malfunction and fire off on on side only?

 

Backfiring through the carb is almost always from being too lean. When you're tuning the carb, you lean it out until it backfires through the carb, then go 1 richer.

If you still have the original coil, it is not possible for one cylinder to not work right. You can also swap the leads at the coil and prove that to yourself.

Did you take the carb apart and thoroughly soak/clean everything or just spray carb cleaner down the throat? And spray a little bit of carb cleaner directly on the junctions, as I said, while listening. Not some spray in the general area.

 

I spayed the junctions like you said. I did not have time to completely clean the carb just down the throat. I did replace the plugs, they were VERY black. It seams to run good now but it is 78 degrees today. How do I richen up the fuel mixture. I can't seem to find any adjustment screws. Do I need to pull it off completely? What would cause the plugs to foul so quickly?
I'll check back tonight after work. I'm off tomorrow so I can get at it good.
Thanks so much for all of your help. Brian