What Is This Noise? (video)

[daredevil95]

Hi, I have a 1998 GS 720, the ski is in great shape for it's age, it recently started to vibrate and have no power. I changed plugs, wires, solenoid, rear electrical box harness and coil. This work did not fix the problem, I think I miss identified the problem as the engine breaking up while it might be a drive line issue. it has 160ish psi compression in both cylinders. I installed a new solas impeller and wear ring last year, the carbon seal ring looks good so, maybe the jet pump? I couldnt find any examples of a bad pump or drive line noise. The end of the video shows jet pump / engine running....I didn't notice the sound until I watched the video but, I'm by fa no jet ski expert....this is my first jet that I bought last year. Thanks

 

[Old dog 68]

the pump is a little noisy> i would pull it and check bearings and oil. be careful running it so long out of water even on hose. the carbon seal is cooled by lake water and will get hot and burn up out of water. remove the pump and run it and check for noise and check back

 

[daredevil95]

the pump is a little noisy> i would pull it and check bearings and oil. be careful running it so long out of water even on hose. the carbon seal is cooled by lake water and will get hot and burn up out of water. remove the pump and run it and check for noise and check back

Thank you! I wasn't sure if I could run without the pump on....I'm gonna work on it today and we'll see what happens? hope it's as simple as a pump? Thanks again!

 

[POPPS]

I'm with the Dog, sounds like pump bearings,,,pull the pump, Betcha water comes out of the pump cone,,,the carbon seal will not make that vibration.,,,Put your hands on the rear body of the ski, if you can feel vibration, then its your pump, or a bent shaft,,,to check for that, go under the ski, have a strong flash light,,have someone start it,,,you will be able to see a bent shaft easily from there.

 

[daredevil95]

I'm with the Dog, sounds like pump bearings,,,pull the pump, Betcha water comes out of the pump cone,,,the carbon seal will not make that vibration.,,,Put your hands on the rear body of the ski, if you can feel vibration, then its your pump, or a bent shaft,,,to check for that, go under the ski, have a strong flash light,,have someone start it,,,you will be able to see a bent shaft easily from there.

I removed the shaft & pump today. Brownish oil came out of the cone so, looks like water was in it but, not much? Definitely more oil then brownish but, yes...I'm guesing bearing. I have a old pump housing that I'm gonna try out tomorrow. I ordered a new cone Just for the O-ring; my spring and cone is in good shape. The drive shaft seems straight....I rolled it on the bench and it seemed good?? I also ran the Jet ski with the pump and shaft out, Seemed smooth but, I didn't run it long....In my garage raised up on jack stands. Didn't want to make a mess.

Quick question to everyone, will a bad pump bearing cause the ski to loose power? The clanking sound I understand so, I'm hoping it's the pump. I'm a car guy so, I'm in my learning curve with jet skis.

Thanks in advance!!!!

 

[Old dog 68]

By the way nice looking gs. I love mine of course the gsx is faster but I still love riding the blue donkey. My favorite all around hull design

 

[daredevil95]

By the way nice looking gs. I love mine of course the gsx is faster but I still love riding the blue donkey. My favorite all around hull design

Those are mint!

 

[POPPS]

If the pump bearings are done, they will fall out of the housing,,and worn chewn bearings will definitely make the ski run crappy.