I know I am posting on an old thread but I am having a similar issue.
except my ski is acting like it IS running off of the battery.
I just bought a 88 JS550. Never owned one before and this past weekend I taught myself how to stand up on one... yay me. but I sure did not have it easy. I charged the battery because it was dead when I got the ski. The batt held a charge in my garage for 3 days so I figured im good to go.
I launch it in the lake and fell off about 20 times... every time I fall off the motor dies (carb was set poorly)
finally get sick of it cutting out so I go to shore and adjust the carb.
I go to do a off shore take off and 10 feet later the ski acts like it has no power and sputters to a stop. The batt is now dead and cant turn over the motor at the speed needed to start. I grab my booster pack and it fires up but when I try to take off it dies again in 10 feet.
I hook up the booster pack and have a smoke then start it... then apparently the 10 min I took to have a smoke while the booster pack charged up the batt was enough for me to get 100 yards out of the ski before sputtering to a stop
then I pull the battery and charge it over night. this morning I put it back in the ski and I rode it on the lake for about 20 min with the ski acting flawlessly. I let go of the throttle and it idles... I hit the throttle and it revs up and takes off like a bat out of hell... but after 20 min of constant running the damn thing just sputterd to a stop on me again.
it has plenty of fuel
the carb is set right.
the batt wont supply enough juice to turn over the motor (yes I know the first 2 have nothing to do with the batt)
my issue here is if the ski cant run off the batt even if it needed to...... then how is it that im running my batt down running my ski?
and with my volt meter im getting 12.5 volts off the batt when running and that number was lower and lower every time I checked it until it quit only giving 11.3 volts when it shut down the last time.
everything on my ski appears stock....
I am just bugging out looking at a $300 stator assy for a $500 ski
shoot me a few ideas ANYONE before I swill enough
to dump waaay to much money in a ski that prolly aint worth what I am thinking of doing.