popping back through carb

[sreetmetal]

so I have an 81 Yamaha xs400 I just installed a new PAMCO electronic ignition and new carburetors from Mikes XS I cannot get the bike running since I have installed parts all I am getting is a popping from the right carburetor?

 

[BBS360]

May be totally irrelevant with the pamco ignition, but I had very similar issues with my points.
Turned out the timing cam on the end of the cam shaft was installed the wrong way around. Flipped it and the bike started first try.

Of course you don't have points with a timing cam to insert the wrong way around but it could be a timing issue. Did you rebuild the top end at all?
Also, which carbs did you get from Mike's?

 

[Curseduth]

I was just having the same thing happen when I had my orange and gray wires switch after switching to the TCI from points ignition. Backfiring through the right carb. What is it with the right bank getting all the hate..

 

[2005c50]

Did you try checking the ignition timing with a timing light while the engine is cranking?

...........Paul