Bought waverunner 3 weeks ago hoping to go fishing but have been working alot. I am in the Houston Galveston area.
Tried to crank up jet ski after 3 weeks of sitting but battery went dead, jumped it and got it started but would not stay running at first, kept starting it and it was running very rough. Kept it running for about 20 minutes then it lined out. Could this be old gas or could it need a tune up. It ran excellant when we went for a trial run
and cranked right up. I will need to make a few trips before I can feel comfortable with it Any ideas?

charge the battery with a atv or motorcycle battery charger. if the jetski is still running sluggish, check the spark plugs. i don't think it's anything with the oil..

Found what I done wrong, I know it sounds like I should have known but I just got it. Well I was flushing out motor and turned it off but kept water running. Well I did not know the engine needs to be running anytime water is going in. Expensive lesson learned. Got water in engine.