Jump to content

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

Thruster Cavitation


Recommended Posts

The thruster on my 2021 M220 works flawlessly with the engine off.  When running the engine, the truster works great moving the stern to starboard, but about half thrust moving the stern to port.  I seem to be getting cavitation from the surf pipe air bubbles.

 

For those of you with factory installed thrusters - is this happening to you?  Or is this a M220 thing?  

Pic of my thruster install location for reference. 

 

image.png.8784ffdd40c2e4afc1a1a78e5a053275.png

Link to post

Mine is in the same spot on my 25.  I will get some on my 25 if I run it on for any length of time.  I have gotten into the habit of using shorter bursts while letting it drift and being patient with it.  I think that also helps with as much of a power drain as it causes.  If I am trying to spin a full 90 or 180 degrees, I don't do it all in one burst.  When I use it to back into my slip, I don't have any issue as we are going slow and making minor corrections.

I would think it might be a product of the surf pipe itself and the exhaust rising.  Moving to port, it is trying to pull water with something the size of a small oar 4 inches away from it causing a disruption in the water as well.  

It could be the bubbles, it could be that it spins faster with the engine running, it could be that it is trying to pull water through with the surf pipe right there disrupting the water being moved or a combination of all.  Those little buggers draw a ton of power and I'd guess they are getting more spin with the HO alternator going.  

Link to post
22 hours ago, JeffK said:

I would think it might be a product of the surf pipe itself and the exhaust rising.  Moving to port, it is trying to pull water with something the size of a small oar 4 inches away from it causing a disruption in the water as well.  

Agree 100 percent. Not the best location for a thruster but not a better option for placement on these boats. Short bursts and patience is key. Same technic we use on large ocean going boats. 

Link to post

Unfortunately this is normal across all the brands. The exhaust gets in the way when moving to the stern in the port direction. 
Nautique added a secondary exhaust outlet further up on the transom to be used when the thruster is engaged, diverting exhaust away and avoiding cavitation. 

Link to post
1 hour ago, The Hulk said:

did they ever? im guessing if they did it was too expensive and didnt sell any. 

They did. Expensive, leaked, took up storage space, didnt work all that great. 

Edited by COOP
  • Like 2
Link to post
On 10/29/2021 at 12:46 PM, The Hulk said:

did they ever? im guessing if they did it was too expensive and didnt sell any. 

There wee several that sold.

I'd say it was people who chose all of the options to be "baller".

Link to post
On 10/28/2021 at 7:14 PM, Cole2001 said:

Unfortunately this is normal across all the brands. The exhaust gets in the way when moving to the stern in the port direction. 
Nautique added a secondary exhaust outlet further up on the transom to be used when the thruster is engaged, diverting exhaust away and avoiding cavitation. 

Yep.  It is exhaust bubbles causing the cavitation.  just part of the design with lots of stuff back there.

Link to post

Regardless of the issues.  We love our stern thruster.  Primarily use it around the docks to counteract current and prop turn when docking and leaving dock.

  • Like 2
Link to post

Are you guys using it while in gear, fwd/rev , I would think with some propulsion moving through the water would aid in the speed of the thrust direction.

I only have about 1hr of experience with stern turn, ( on @Dfowkes) M240 but it was enough to put a smile on my face and a check in the box for my 2022.

 

  • Like 2
Link to post

@Stevothat make me so happy as the lack of stern thrusters was one of the main reasons I sold my m235 this fall and bought a 2022 m240.  Boat is in winter storage so I’m looking forward to trying it in the spring.  

Link to post

It is disappointing that this happens in the one direction I actually need it to get into my dock.  Ordered for the first time and anxious to play with it.

Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...