Engine vibrating and produces almost no thrust

[Rickson]

Hi all,
I am hoping someone can help me with some ideas on where to start. I was out on the boat yesterday and having a good time. We had backed into an island and were leaving when the motor started to vibrate very badly. I couldn't really get it above 3,000 RPM's without it shaking crazy. It allowed me to go at no wake speed and after several hours I made it to our launch point. It was late and dark, so I couldn't do much once we got it out of the water. I think I might have sucked a rock into the impeller, but not sure. Is that what it sounds like to you guys?

2015 Yamaha SX190

 

[ruztew]

Sounds like cavitations caused by something in the impeller area... Look up there with a flash light and worst case pull the pump assembly to investigate...

 

[Trevor Shipman]

Plugs in?

 

[Matt Phillips]

Make sure your plug is seated completely. Otherwise as mentioned above, you may have a rock in there or something. I will also get milfoil around my ride plates and will have to reach down and clean that out.

 

[Julian]

Sounds like something in the pump.....did you pull the clean out plug to see if there was something in there?

 

[Rickson]

Thank you for the replies,

I will check the plugs (I didn't even think of that) and see if I can get a better look into the impeller.

 

[Rickson]

Yes and nothing in the clean out plug area that I could find.

 

[Scottintexas]

did you stick your hand down there and feel around the impeller? You may have to crawl underneath and look up through the grate at the front of the impeller, it could be as small as a toothpick or piece of fishing line,

It also could have fallen out when you took your boat out of the water so it may be worth a short water test to see if it's still happening,

 

[Cobra Jet Steering LLC]

Here is some advice, be very careful backing in any shallow water, you are kicking up the bottom and placing it in your intake grates. you mentioned that you backed into an island, this most likely placed weeds or other trash in your pumps and the result was simply cavitation, learn my reverse move to quickly eliminate any trash in the intake grates.

 

[tdonoughue]

I have also had it where I sucked up a little piece of wood that jammed in between the housing and the impeller blade. Jammed in there good. Wound up having to take off the grate and picking at it with needle nose pliers to get it out. So check around the impeller from both sides. That reverse move works well with most stuff, but now and then you can get just the right sized thing in there....

Good luck and let us know how it goes!

 

[RiverRat]

I also had a piece of wood jammed between the impeller and the wear ring and my boat acted exactly as you described. I was able to get it out by reaching in the clean out and also attacking it from behind, by putting the throttle in in forward and laying on the swim deck and reaching through. About 3 minutes and I was back on my merry way.

 

[jameskeller76]

While this won't help your current problem, for the future when back into shallow water:
1) drop your anchor at the bow when the water is still deep(ish). Leave slack in the line
2) Start backing up, get some momentum and kill the engine and glide it in
3) Once you are where you want to be set the anchor and tie off
4) tie a second line to shore to secure your boat

I've only had my jet boat for a few months and getting stuff in the impeller is part of life. Good luck!

 

[OrangeTJ]

I'd say it is almost certain that you have something stuck in your impeller. Most likely something very small stuck between the impeller and the wear ring. Unfortunately it can be tricky to spot or feel this through the cleanout port, but dollars to donuts it is there.

 

[Ronnie]

There is also the possibility that you had something floating in the intake area before the impeller and that it dropped out when you pulled the boat out of the water. if you don't find anything obvious take it to the water anyway to see of the problem fixed itself.

 

[itsdgm]

@Rickson i agree with all of the above members. Your issue sounds like cavitation, more than likely something tiny stuck in the pump or on the pump shaft. Keep in mind that anytime you have a loss of thrust, there's also the potential for a significant reduction of cooling water flow in the engine. Our boats are cooled by taking water from the pressure side of the pump. Loss of pump pressure means loss of cooling water. I'm sure you're on the safe side of things if you didn't get any alarms or warnings. But it's always a good idea to fix the cavitation ASAP. Usually it only takes a simple check and removal of debris in the cleanout plug area.