Motorcycle Repair: Engine cuts out on one side. 1976 BMW R 90/6, jet needles, bmw r 90

Question
Hi Chris,

Have good gas flow from tank.  Filters clean.  New plugs.  Timing on.  Carbs balanced. Valves recently adjusted.  Carb jet needles in proper position.  When coasting to halt with engine off after 1/2 mile at 70, cutting out, rt side clean, lt side with some dark deposit.

Please give me a hand or submit to message board.

Regards,

Ralph in Montana

Answer
Hi Ralph.
 You could have a couple of problems here.  Since you live up north, my guess is that the bike spends time in seaonal storage.  This means that the carbs may have residue built up in them that we call varnish.  That is removed during a thorough carb cleaning and cleaning or resealing the tank.  In the future, to reduce that build-up, store the bike without fuel in the tank or carbs.

 There is also the possibility of a short in the ignition system.  Check the entire ignition system as well as all of the ignition components (as per the specs in the repair manual.  Look for failed components, shorts, bad connections and anywhere that there could be arcing against the frame.

Good luck.
FALCON