You will find the gray hoses to be an issue with that year of ski.  Also... you may find the fuel select valve to be plugged up.
BUT... yes... it could be your lanyard, or post... or some other electrical gremlin, but electrical issues don't show up with throttle positions.  They could show up at a given RPM though.
If it is electrical... and it's showing up at a given RPM... I would point my finger at the regulator/rectifier.  When they go bad... they generally give high voltage.  When that happens, the engine will do all kinds of strange things.  (but doesn't normally just shut off)
Do this...
Start the engine, and put a meter on the battery.  It should be around 12.5v.  Then bring the RPM's up.  If you see more than 14.5v (@5000 rpm's)  then the regulator is bad.
If your voltage is good... change your hoses, clean the valve, fuel filter, and carbs.