impella noise

[tabe85]

hi guys
i have a rx 00 seadoo with a 951 in it out of water the impella makes crazy noise reving and at idle i no this noise is normal but not that loud has it got any thing to do with me premixing the fuel and bypassing the oil pump
done a search on it and it came up with a thread sayin they have oil pump line going to it
or if i just ignore it will it do damage
thanks guys

nathan

 

[seadoosnipe]

Thrust bearing....

What your hearing is the vibration created from the thrust bearing. You have 3 bearings in your pump. You have two jounal, caged needle bearings. These bearings take up the radial (side to side) movement in your shaft.

The bearing making the noise is your thrust bearing (takes up axial movement, that's back and forth). With the ski in the water, the impeller has the water to push against. That means the shaft has torque pushing itself against the thrust bearing with some pressure. Out of the water, the shaft is kinda floatin back and forth. There is no water for it to push against. Kinda like that thrust bearing is not needed if you have no torque pushing against it.

So what your hearing is normal. They make a kit that is basically a spring that fits into the nose cone to put spring tension on the shaft. But, I'd not waste the money on it. It only works for a short while till it gets to weak to hold it tight........... So, don't worry with it, it won't hurt the motor or pump.:cheers:

 

[crisso]

Bearing noise

I read what you wrote about the bearing noise.Very helpful.Thank you.Along the same lines.How long is a safe period to run the ski with the flusher hooked up and the water running.Not how long to flush the motor but how long before something in the pump may be damaged if you are running the ski out of the water.It,s something that would be good to know.Thanks

 

[96seadooxpBC]

ive learned from reading through here to not let it run out of water with the hose on for more than 5 minutes, something about how the jet pump and impeller bearings etc are cooled by actually sitting in the lake/ocean water.

cam

 

[seadoosnipe]

Time limits...

ive learned from reading through here to not let it run out of water with the hose on for more than 5 minutes, something about how the jet pump and impeller bearings etc are cooled by actually sitting in the lake/ocean water.

cam

This is true. The manual calls for a 5 minute time limit. But honestly, I've run my 787 in my Challenger for upwards of 30 minutes.

There are two things to look at. When you back flush, you are running the water through your engines cooling system backward. So, your not actually giving the engine it's proper flow path for cooling.

The other reason they suggest 5 minutes is the shaft seal. The water helps to keep the shaft seal cool and lubricated.

What I did when I was tuning is made an adapter for bringing my hose cooling water in at the cooling waters inlet to the motor. Then, I put a hose under my boat with the nozzle that you can set for a fine misted spray to shoot into the suction side of the pump. You do these things and you can run for a lot longer. But, make sure that if you do, when you start the motor, turn on your water hose only enough to see water from the tell tale hole. Do not turn it on with full force..........:cheers:

 

[crisso]

Thank you for your answers on running out of the water.Little things like this are good to know."everyday a bit smarter":cheers:

 

[seadoosnipe]

I love it!!!!!!!

Thank you for your answers on running out of the water.Little things like this are good to know."everyday a bit smarter":cheers:

And that's what I love the most about being in this forum. Everyone is here to help everyone out. Just a month or two ago, I had a question myself about my own boat. I was kinda stumped so I made a post. One of our members, Dennis (we call him DAWG) had an answer to my problem on his first shot. Goes to show you that all of us can learn something new everyday by being in this forum.............!:cheers:

 

[96seadooxpBC]

This is true. The manual calls for a 5 minute time limit. But honestly, I've run my 787 in my Challenger for upwards of 30 minutes.

There are two things to look at. When you back flush, you are running the water through your engines cooling system backward. So, your not actually giving the engine it's proper flow path for cooling.

The other reason they suggest 5 minutes is the shaft seal. The water helps to keep the shaft seal cool and lubricated.

What I did when I was tuning is made an adapter for bringing my hose cooling water in at the cooling waters inlet to the motor. Then, I put a hose under my boat with the nozzle that you can set for a fine misted spray to shoot into the suction side of the pump. You do these things and you can run for a lot longer. But, make sure that if you do, when you start the motor, turn on your water hose only enough to see water from the tell tale hole. Do not turn it on with full force..........:cheers:

great info! this explains why yesterday when i was running my xp on the hose, it got pretty hot, hotter than it normally would while running in the lake( When riding my ski i stop every 20 mins or so to take a break and check my engine block temperature with my finger, see if it burns ahahaha, i know thats what the " pisser " is for, but im obsessive and i NEED to check these things to reassure myself ive got good cooling )

I wondered why this was so, i knew it wasnt because the hull wasnt in the water, but this explains alot. while looking at my cooling system and where the hose went in, it looked like it wasnt the correct flow path, maybe i didnt have my hose on enough for proper pressure throughout the system. thanks for filling the blank!:cheers: