Brief cavitation

[Chwtom]

just picked up a 14 195 HO. Runs great, except one issue. If I gun it, it seems to bog down for a few seconds, then runs fine and will get up to 45mph with no issues.

I'm guessing there's a little cavitation, but if it's only happening when I gun it, would that be a seal issue or a design issue?

 

[ScarabMike]

When you throttle the pump at full speed, it takes the pump a couple seconds to be able to produce thrust because the impeller is spinning so fast, and the boat is sitting still, that it cannot get fed enough water to shoot through the venturi. You will also see this if you ride on some tall chop or waves, and the boat loses contact with the water as you jump the waves.

Some racing PWCs will change the intake grate to a top loading grate to force more water into the pump, and to keep the hull more planted on the water.

Think of it the same way a tire would if you gun the gas on a race car. It takes a few seconds to get traction.

Sometimes depending on conditions, you will even hit the rev limiter when you go from stop to full throttle. This is normal.

 

[Julian]

Anything more than a second or two would not be normal....and might indicate missing intake sealant, damaged impeller or bad impeller clearances.

 

[ScarabMike]

Very true!

Anything more than a second or two would not be normal....and might indicate missing intake sealant, damaged impeller or bad impeller clearances.

 

[Ron@Scarab]

A long NO WAKE Zone can cause a brief hesistation since the water box or muffler is getting loaded up with water and needs to clear!

 

[ALAN MANN SR.]

I have a 2015 165 HO with a stock intake grate and I have no hesitation except when the hull leaves the water.

 

[wango tango]

does anyone know what the part number for RIVA intake grate for a 195 2017

 

[Cobra Jet Steering LLC]

just based on your own description of the problem
" If I gun it, it seems to bog down for a few seconds, then runs fine and will get up to 45mph with no issues."

leads me to believe you were complaining that the engine itself boggs down if that is your complaint it would be a fuel issue Cavitation is the engine spinning like it is getting no bite in the water for a few seconds then it gets going ok. If you have cavitation it could be an issue with the pump.

 

[Chwtom]

I don’t think it’s a fuel issue, but I’m not an expert. It bogs down long enough that sometimes it’s a challenge to get skiers up. It sounds like to engine revs too high, then eventually settles in.

I took it to the dealer who said it was fine. They called scarab who said it was an engine problem. So they called BRP who didn’t know what was wrong.

By the time they did all that it was the end of the season and the dealer asked me to bring it back in spring so they could test it in the water. I think they asked me to come get it because it was the end of season and they had nowhere to put it, and had no idea what was wrong or even if it was a problem.

I do think there’s a problem. It should take that long to get up to speed. My friend has a twin engine scarab that has no issues like this, I’ve driven it.

 

[Cobra Jet Steering LLC]

Now you are describing cavitation in the pump.

 

[swatski]

I don’t think it’s a fuel issue, but I’m not an expert. It bogs down long enough that sometimes it’s a challenge to get skiers up. It sounds like to engine revs too high, then eventually settles in.

I took it to the dealer who said it was fine. They called scarab who said it was an engine problem. So they called BRP who didn’t know what was wrong.

By the time they did all that it was the end of the season and the dealer asked me to bring it back in spring so they could test it in the water. I think they asked me to come get it because it was the end of season and they had nowhere to put it, and had no idea what was wrong or even if it was a problem.

I do think there’s a problem. It should take that long to get up to speed. My friend has a twin engine scarab that has no issues like this, I’ve driven it.

I experienced this the first time I "upgraded" to an aftermarket Solas impeller in my 190 (single engine) yam.

There are many factors that effect cavitation (ventilation, impeller slippage). An out of specs impeller is probably the number one culprit.


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[Cobra Jet Steering LLC]

I had that issue with every 4 stroke sea doo pump I owned , maybe it was just my luck but The single angle bearing setup was horrid and one of the reasons I won't own a sea doo ,one of the reasons but not the only one. I hated the hole shot cavitation .

 

[Chwtom]

It’s still under warranty. Is there any way to make them do something to fix it?

 

[Surferd15]

A way to help load the pump more for everyone is a Lucky 13 pump cone. I have a Seadoo GTR ski that leaps outta the water. I also installed one on my Seadoo 150 speedster boat. Same engine setup etc as the scarab. I am running a solas with a metal wear ring and aftermarket grate. But the pump cone totally helps keep it loaded to prevent cavitation. Check the wear ring around the impeller should be smooth a little scratching is normal but chunks missing, deep groves etc is not. This is like 80% where all cavitation exist.