Rear noise

[Bruggar709]

When flushing the engine today I noticed what sounds like a rattle when I give the boat a little shot of gas. Could this be normal?

 

[Cobra Jet Steering LLC]

flush it with some Pepto Bismal that should quiet the rear noise

 

[Sean R]

Yep its normal. Sound like a bunch of ball bearing rattling around?

 

[Bruggar709]

what is the cause and is there a way to eliminate it? Sounds like the back of boat is falling apart.

 

[Cobra Jet Steering LLC]

Did the boat sit for a while? As they sit the pump liner swells from dissimilar metal corrosion if you look in the pump liner there will be hot spots in the liner usually dark spots this is where the liner is swollen and contacting the impeller , If you use the boat it keeps it worn down but when they sit it comes back and if it sits too long it can even lock up the pump . But when running in the water you don't even notice it . https://jetboaters.net/threads/low-budget-fix-for-yamaha-pump-liner-swelling-issue.12121/#post-259021

 

[Sean R]

I've had two Yamaha's jet boats and when flushing (on the trailor) the engines are a rattle box, but on the water no rattle. It does suck cause when I am at the house doing maintenance/cleaning i want the eng to sounds strong like my old Searay with a 4.3l did and it made me feel like a cool guy in frt of the neighbors These eng I don't feel as cool. One time my neighbor was out when I was flushing the Yamaha and he said is your eng running right 500 hrs total on both Yamahas. Go on YouTube and see if your eng sounds like the "how to flush yamaha" videos.

 

[Cobra Jet Steering LLC]

you can change out the metal rings to nylon rings I only use those now I get them at sbtontheweb.com you change out the housing and then in the future you only have to change the nylon ring if it gets damaged I put a lot of hours on those with great results.

 

[2kwik4u]

what is the cause and is there a way to eliminate it? Sounds like the back of boat is falling apart.

It's the stainless wear ring and the stainless impeller rattling around. No water pressure in the pump to keep it seated, and there are small clearances in both parts.

Sounds terrible, but is perfectly normal on the trailer.

 

[Bruggar709]

THANK YOU