Noisy pumps at idle

[jethrof16]

It used to be just the port pump that was noisy at idle but now both of them make a lot of racket at idle. I usually go to "No Wake 1" to make them quieter so we can talk. I don't notice any unusual vibration at any other RPM other than idle. Is this normal? I have a 2018 242X with 250 hours. Thanks.

 

[Cobra Jet Steering LLC]

Dissimilar metal corrosion between the stainless pump liner and the aluminum housing, causing high spots it the pump liner, very common I believe Yamaha has now gone to plastic liners in the new pumps! When the boat sits the high spots get larger so when you start the boat for the first time of the day on the trailer you will hear it the loudest, however if the boat sits long enough I have seen the pumps lock up or slowdown the starter from drag and the drag can harm the starter over time.
If you ever experience this dragging of the starter turning over the engine for only the first time of the day you need to replace the pump liner sections, and if it is real bad and won't turn over fast enough to start just spray some W D 40 in the pump around the impeller and the engine will usually start.
After it starts the first time it will usually start ok the rest of the day only to have the same issue next time it sits for a while I am giving you this info so you can realize the true cause as a lot of people get a new battery or starter when it is really the pump and a few people have sold the boat thinking it had seized up engines when it was just the pump.
I replace the liner sections with nylon liners and get good service out of them . I also like the fact that I can replace JUST the liner if it gets worn and not the entire housing section.

 

[anmut]

My port engine is noisy at idle when i flush it, but I can't find anything when I inspect it to determine the cause. Sounds like gravel being turned by the pump but only happens at super low RPMs. This has been the case since day 1 with the boat.

 

[mrcleanr6]

All jets, both boats and skis are noisy when you run them out of the water. Its completely normal

edit: the impeller should not be rubbing the housing and making noise. they generally will clank and be noisy out of water at idle not under load from the engine coupling

 

[Cobra Jet Steering LLC]

Mine make no noise since I removed the pump liners and replaced them with the plastic liners . And if you want to check spray WD 40 in the pump and then listen to it and it will be quieter.

 

[jethrof16]

Mine make no noise since I removed the pump liners and replaced them with the plastic liners . And if you want to check spray WD 40 in the pump and then listen to it and it will be quieter.

Good info...thanks. Do you guys sell the nylon liners? Would this be covered under warranty? This noise is very noticeable in the water.

 

[jethrof16]

All jets, both boats and skis are noisy when you run them out of the water. Its completely normal

edit: the impeller should not be rubbing the housing and making noise. they generally will clank and be noisy out of water at idle not under load from the engine coupling

I understand the "out of the water" situation but my post referred to noise with the pumps submerged at idle

 

[anmut]

I understand the "out of the water" situation but my post referred to noise with the pumps submerged at idle

My port engine also makes noise at idle in the water.

 

[Cobra Jet Steering LLC]

That could be from bad bearings or bad intermediate bearing also , what type of sound are you referring to.

 

[anmut]

That could be from bad bearings or bad intermediate bearing also , what type of sound are you referring to.

It only seems to be at just above idle speed and only at a certain RPM, it's a metal clanking sound. I've never worried about it because it's done it from day one. I'm going to try the wd-40 spray though next time it's out and see if I can narrow down where it's coming from.

 

[Cobra Jet Steering LLC]

well that one eludes me possibly harmonic balancer or vibration dampener at the back of the engine

 

[anmut]

well that one eludes me possibly harmonic balancer or vibration dampener at the back of the engine

I'm going to have the dealership look at it in the off season just to make sure it's not an issue that will lead to failure later. I've even thought that I could pull that pump and just that act might reset it. Would be a good exercise too.

 

[jeffrt]

My boat does the same thing, and it too smoothes out with no wake mode on. Curious to see what you find.

 

[Cobra Jet Steering LLC]

I have a difficult time trying to imagine being able to hear the pump when it is in the water, especially with it behind the engine compartment with all that noise.
I have had many a pump hatch but you feel it more that hear it, I just wonder if you have an ignition or injector issue and it is making the engine make noise or vibrate at slow speed and it just sounds like a pump noise, the basic identifiable sound from the pumps is on the trailer ringing that I described previously.

 

[jethrof16]

I have a difficult time trying to imagine being able to hear the pump when it is in the water, especially with it behind the engine compartment with all that noise.
I have had many a pump hatch but you feel it more that hear it, I just wonder if you have an ignition or injector issue and it is making the engine make noise or vibrate at slow speed and it just sounds like a pump noise, the basic identifiable sound from the pumps is on the trailer ringing that I described previously.

there is no doubt my banging sound is coming from the pumps at idle in the water. It's the 3rd season with new plugs and filters this year. absolutely not a rough running engine.

 

[Augieol65]

I have also been chasing this since day one. I have a rough sounding pump at idle (1300 rpm) the second I increase rpm to no wake setting one (1700 rpm) it smooths out and is quiet. I wondered at that low speed if turbulent water or flow is causing minor cavitation and noise? I plan on redoing the sealant around the pump housing soon to see if it helps.