I just got off the lake after being towed in after the battery died, but for the last 6 months I have had issues with my jet ski not accelerating to top speed as it did when I first bought it. I first noticed it in the spring time after winter. I didnt winterize it because I ran it throughout the winter season.
At first it just felt like power surges where the jetski would lose power and then surge forward again at full throttle. After a while of that, it just wouldnt reach top end anymore. The speedometer would read about 50 as opposed to 65. A couple of months ago the battery notice would come up on the screen. I didnt do anything about that and today the engine was severely compromised. Top end of 45 with very poor acceleration. It was also going from 45 to about 15 at full throttle thoughout the hour that I ran it. When I stopped, the engine died and wouldnt turn back over so the battery is for sure dead.
Can anyone help me with this. Is it possible that this has always been a battery issue???
thank you so much for the help,
coleman mcmurphy

 

Your problem symptom could be either electrical or mechanical.
What is your battery voltage reading?
What is the compression reading on each cylinder?
Have you noticed any smoke coming out from exhaust?
How is oil level and its color?
How cold did the temperature get during the winter? The exhaust manifold could get cracked by freezing water inside if not drained properly. Any water in the hull right after you run the unit?
Jetski speedo is not an accurate gauge. What is the maximum tach reading at wide open?
How is the impeller tip to pump clearance? Just to make sure it's not a cavitaton problem.

If you are not planning to take the ski to a dealer, you will have to do all the above checks by yourself in order to diagnose properly.