Running / ignition problem

Hi
Still working through a friends bike.
The bike starts up & runs. The timing side has a smooth exhaust & the pipe gets hot. Drive side is rough & pops & bangs, the pipe gets warm.
The bike now has new carbs new coils new plugs new leads. A new Boyer with the wiring replaced from the pick ups & as per the Boyer wiring diagram between the coils.
I have adjusted the throttle stops up. Done the tappets checked the timing. Out on a run the bike runs great once back in traffic the popping & banging starts again. Drive side only.
Now when I pull the spark plug cap (Tuning the carbs) the engine picks up & runs really well (the tickover races) when I put the cap back on the plug properly the popping & banging starts again?
Your thoughts?
I intend jury rigging the ignition direct to the battery ignoring the wiring harness as my next test as I wonder if there is a problem on the negative side.
all the best Chris

Intake air leak? Haven't had this problem on the Norton, but had this exact same problem with a Yamaha Roadstar.

Chris said:

Hi
I have adjusted the throttle stops up.

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Throttle stops are one thing, cable adjustments are another.

Put your fingers on both slides at the same time and turn the throttle slight to reveal whitch one moves first. The throttle stop screws should be all the way out to let the slide rest on the bottom. Adjust the cable to equalize the slide then go back and set the throttle stops.

Chris,
Hope your not just popping off the plug wire to check the carbs. To use this method with what we know now you would take a spare plug grounded to the head and switch the plug wire cap to this grounded plug. If you just remove the wire while running the spark will come right out the side of the coil with very bad running from then on.
Check your plug leads for resistance both sides, check your coils for OHM resistance both sides. Have you a very good ground from the coil at the end of the power string and is it also grounded to the Boyer box? Is the head grounded? Have you checked your NJ's on both sides with a .106 gage to see if they are a pair?

Check after dark too, plus tugging jerking pounding stuff. Might verify the trigger leads are on in correct order reversed does stange things to timing but both sides i found. General rule of thumb is symptoms seem electric think carbs first. Another rule of thumb more than one things at once can cause same symptoms. Prove your man hood and get er hot with running smooth sounds.

General rule of thumb is symptoms seem electric think carbs first

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Agree with that one, had two troublesome 750's on the bench this year with similar issues, at the end of the day both were carb related (blocked or semi blocked pilot circuits)
Worth swapping the Boyer if you're at your wits end, seen these doing strange things, slowly changing over all of mine to pazon

Hi Thanks for your responces so far.

The cables are spot on
We have adjusted the throttle stops up on the poor side to run faster than the good side. Faster tickover same symtoms.
Personally I have always suspected one of the new carbs. I have adjusted the float height. I intend fitting a single carb manifold & fitting the right hand carb to it. Hopefully I will see if there is a manifold gasket air leak before doing this.
Boyer. Not the problem as it was fitted with a Lucas Rita. I replaced the control box with my spare then a complete Boyer system. Nothing altered.
I will check the carbs for an airleak then jury rig the boyer direct to the battery. After that I will single manifold it & fit the right hand carb. I cant see a problem with the left hand one but it just feels right to me.
I will post at the weekend with results
Thank you all.
Chris