Right Side Rich

I noticed slight smoking and popping from the right exhaust. I pulled both plugs and the right side is rich (black and sooty). Since I have a single Mikuni, and no points, I suspect weak or intermittent spark. Have the electronic ignitions been known to be problematic in this way ? Any other possibilities ? What would you suggest as a logical sequence for confirming the problem ? TIA

71 Commando

wit61 said:

I noticed slight smoking and popping from the right exhaust. I pulled both plugs and the right side is rich (black and sooty). Since I have a single Mikuni, and no points, I suspect weak or intermittent spark. Have the electronic ignitions been known to be problematic in this way ? Any other possibilities ? What would you suggest as a logical sequence for confirming the problem ? TIA

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Sounds like maybe a worn valve guide on the ride side? That might explain the fouled plug. Had a similar problem on my Triumph TR6C that was cured with a top end rebuild including new valves and guides. Not sure how worn valve guides would cause a popping though.

Be careful that the rings on the "rich" side haven't taken a proper set. It goes like this : Hone was a bit too fine say 300 grit or more lots of modern machine shops use the latest tech but that don't make it right. Than taking some bad advice it was run very gently during the break in for say 500 miles. Or even worst the assembler used a bunch of oil on the rings,that will gum them up and stop a proper break in. When oil comes into the combustion chamber it lowers the octane rating causes Knocking very bad stuff ensues. You get your fist signal from reading the plugs learn oil from rich on your reads. The second clue is losing valves because of the stem of one hangs up on the carbon deposits. Just pulled down a motor from the bent valve deal the hone was so light that there were no scratches left in the bores and the rings were only worn in for one half of their hight.
Also a good close look at the casting that forms your single carb manifold have you lost one of the bolts inside there? And is the inside every bit as good as it could be? Some of these castings are badly done. Oh, and are you sure that you have a perfect ground from the engine to a common ground on the frame? And the ground from the coil also shares this common ground? Cleaned your kill switch lately? checked your key switch for voltage drop? Switched coils and or spark plug leads and watched to see if the problem moves?
Just to get ya started.