Starboard engine rattling - any thoughts?

[Georg]

Both jet pumps are louder but engines seems good.

 

[buckbuck]

@RXBoost Those sound just like my MR-1 motors. You're all good. When you get a chance change your title to reflect your new boat.

 

[pmac]

Well I pulled the pump and the sound didn’t go away. Pump looked good, impeller looks new and shaft spins smooth and easy.

Starboard no pump video

View attachment 105658View attachment 105659View attachment 105660

What was the problem? I am having the same issue this year, my starboard engine just started to rattle. Thank you

 

[WestMIJet]

I couldn’t find any issues. They just sound a little different. I have been running them all year with no issues.

 

[Bleasy]

Well I pulled the pump and the sound didn’t go away. Pump looked good, impeller looks new and shaft spins smooth and easy.


Was this issue resolved?

 

[Cobra Jet Steering LLC]

did you check the intermediate bearing and vibration dampener on the back of the engine

 

[WestMIJet]

did you check the intermediate bearing and vibration dampener on the back of the engine

I didn’t but will take a look and see if I can isolate the noise to the bearing.

 

[Cobra Jet Steering LLC]

there is a rubber vibration dampener between the 2 aluminum pieces either the engine alignment is off or the rubber may be damaged and need to be replaced

 

[AboveTheBest]

there is a rubber vibration dampener between the 2 aluminum pieces either the engine alignment is off or the rubber may be damaged and need to be replaced

If that turns out to be the problem the good news is you can replace this without pulling the engine.
You’ll need to pull the motor mount bolts and remove the exhaust manifold, and the engine can slide forward enough to change the dampener.

If you need help just bring the boat with you this weekend and we’ll do it at the house...

 

[Cobra Jet Steering LLC]

That reminds me also check your motor mounts as a broken mount will cause the engine to rattle under acceleration also

 

[ToddW850]

@WestMIJet did you ever narrow this down. I've got my port engine doing this, but my starboard not. Mine is louder than yours, however, quiets down after it warms up.

 

[WestMIJet]

I haven’t figured it out but I haven’t put a lot of time into it. I need to check the mounts and the vibration dampener.

 

[ToddW850]

I haven’t figured it out but I haven’t put a lot of time into it. I need to check the mounts and the vibration dampener.

Gotcha. Yeah mine goes away as the engine warms up. Or at least as it runs for a bit. Does yours quiet down?

 

[WestMIJet]

I don’t notice it much when the engine compartment is closed and it doesn’t impact performance. Our boat is kept at the marina, if it was here at home I would dig into it more. The next time I go pull it to wash I will go through it again.

 

[ToddW850]

Thanks @WestMIJet. I don't have any issue with performance either, just the noise. I fired it up this morning and used a mechanics stethoscope, but could not narrow it down.