Thrusters

Contento

Active member
Joined
Mar 12, 2018
Messages
26
Fluid Motion Model
C-28
Hull Identification Number
FMLT2719A313
Vessel Name
Scooter
I have researched the archives but unable to find an answer to this question. Stern thruster on my 2013 R27 quit working. Main fuse on port side under master switches ok. Before diving too deep into trouble shooting, is there perchance a secondary fuse to the console mounted “joy stick?” Bow thruster works fine.
 
Contento,

Does the thruster make no noise at at all? If it does then it is more likely a shear pin. If no noise, I agree a fuse or a bad connection is more likely. Only one fuse for each thruster as far as I know. If the fuse checks out I would look for a bad connection at the Thruster motor, the fuse block, or at the joystick controller.

Curt
 
Check your connector from the joy stick controller at the stern. It should be located in the compartment under the seat. If that checks out okay go on line and follow the trouble shooting guide from Imtra. It could be the controller or the relay in the motor or even the thermal switch. There is a sequence to follow. Unfortunately once you have to check the relay or thermal switch you will have to remove the motor and remove the cover to access them.
 
Ok, digging a bit deeper found stern thruster fuse blown. Replaced it and initially had power and thruster “tried” to work but sounded like it was laboring, then fuse blew again. Not close to my trailer and water too cold to dive but am wondering if a glob of plastic, water plants, etc may have the thruster prop bound?
 
Contento:

It does sound like something is clogging the stern thruster prop. I know the 150 amp fuse isn't that cheap, but try again with a new fuse and pulse briefly with stern thruster pushing to port and then reverse to push/pulse to starboard - and repeat this a few times. This action may just free things up. The 'brief pulse' may be insufficient to cause the fuse to blow. If the thruster does not free up and continues to labor, then stop and wait for the opportunity to get down in the water to take a look inside the thruster tube and prop. If there's no obstruction to the prop then this quite likely means a bearing and/or motor issue. Incidentally, when you activate the stern thruster is it obvious the prop is rotating ?
 
Thanks for your reply Barry and I’ll give your suggestion a try with a new fuse. Not sure if the propeller was turning but sounded like it was, just not “peppy” or “robust” like it normally sounds. I will report back after trying a second new fuse using short right left bursts. On a side note, while in the bilge replacing the thruster fuse I noted my Mase genset mounts have rusted off! Yikes, but then it’s a boat, no?
 
Check the plywood under the screw holes. My wood was soggy and rotten. Determined that the seal around the hatch was not keeping the water out. Further more the lift handle hinge pin let copious amounts of water pass. I replaced the plywood with PVC board, quite a job, under the batteries also. Sealed the hinge pins with a dab of silicone from the inside.
 
Yep, sure enough plywood under the Mase soggy and rotten. Did you have to replace the genset brackets also? If so, where did you source them or can they be diy made? I am assuming with the four corner brkts loose, the genset can be lifted for replacement of the plywood. I too will go with marine board rather than plywood.
 
I think the brackets are part of the frame. If you pull the generator out and take off all the enclosure perhaps an aluminum angle iron maybe secured the generator . I did not have that issue.
You will probably find that under the batteries may need some attention, and while you are at it check the starboard locker from the auto pilot pump to the water heater. :roll: . Mine looked okay until I stepped on it. 😳
 
AliceJ you are just a bubbling brook of good news! OK, one thing at a time, and the first priority item is to finish our trip on down to the Keys and then back home to Charleston where I’ll load ole Scooter on his trailer and tackle the soggy and rotted flooring issues. Much appreciate the heads up.
 
It is possible that the shaft on the thruster has issues and hence the binding. Hopefully it is just stuff stuck in the tunnel. A new shaft is about $500.00
 
I use my GoPro on a pole to check out my zincs. Maybe it would allow you to do the same for a thruster?
 
Update on Scooter's stern thruster. Back in Charleston after a good trip down through the Okeechobee Waterway and down the East Coast to the Keys and back up the ICW East Coast. Southern Florida East Coast ICW definitely NOT on our future wish list! Anyway, boat on trailer and check of stern thruster indicates propeller bound tight, I.E. it will not turn. I'm wondering if it may be the shaft, or gasp, motor? Any similar situations and suggestions? I would like to explore all possibilities before removing the unit, double gasp!
 
Bit the bullet and pull the thruster and motor. My drive unit was frozen from corrosion from a failed seal. Then, removed the motor from the waterproof casing and replaced the front and back bearings with sealed bearings, and replaced the rotted brush holder assembly, again all from corrosion, with a good used brush holder from Side Power. And remember that the motor is in a"waterproof" housing? It's a toss-up on replacing the parts or buying a new unit; if you don't know what you're doing or have a competent mechanic. Side Power was easy to work with in resolving several issues. Of course, there was an issue in removing the drive unit from the motor. Side Power will sell you a metric hex wrench the proper length, but you could buy the hex wrench and cut it to the proper length to fit between the bolt and waterproof casing. Hindsight would indicate that buying the new drive unit and the new motor would have been a smarter move, and saved on the mechanics time. It was about a wash. When you put all this back together remember to put never seize on all the threads, especially the two bolts that hold the motor to the drive unit. One of my bolts were frozen from corrosion and had to be cut off, a big pain! The stern thruster is nice to have, but I did all the canals in Canada and New York without the stern thruster and learned to precisely control the back of the boat. Now that you have done the stern thruster, take a look at the bow thruster, pull the motor, check the bearings and brushes. And remember this is a BOAT (break out another thousand) 😀
 
Thanks for the input Alice J. I agree, the stern thruster is nice to have, but certainly not a necessity. Now on to removal and tear down for diagnosis of the root problem. Are there any tutorials etc. on removal of the thruster that you, or anyone on the List is aware of? It does appear something has been leaking around the unit, as I’ve noticed sea water filling the small compartment where it’s located (limber hole was partially plugged) and dirty water line was above electrical connections.
 
One of the mysteries of the R27 has always been where does the water come from to get into the thruster compartment :roll: I put a small bilge pump underneath the stern thruster to get rid of the excess water, but does not make it dry. But water up to the screw in electrical connectors is interesting because the thruster compartment is open at the forward end that is open to the engine compartment and the keel sump.
When I replaced the plywood flooring in the battery/generator compartments there was drain at the stern of the compartment, water finding its way to the limber hole in the engine compartment. There did not appear to be any draining into the thruster compartment directly. Now it is possible for the water to come up the rudder shaft passed the O rings, if it's not kept greased. :geek: .
The gasket on the hatches appears to be the main culprit, rain or sea water. I have noticed that running at speed with a following/quartering sea, that waves break on to the swim platform and force their way under the door into the cockpit and thence into the lockers. Water also comes through the lifting handles on the hatches. There is a hinge pin that allows water to pass through the handle depression into the locker, a dab of silicone will stop that leak. So far I have not noticed any water in the compartment for the last two months because Alice J is stored in her garage with the door shut :lol:
I would call Side Power to see if they have a walkthrough print out or go to there site and see what's available.
 
Getting the unit out is the easy part. After turning off thruster main switch disconnect cables from battery as safety precaution. Then get to the thruster. Depending on your setup (assume no propane tank) you have to access from rear bench seat. Easier to remove the entire seat lid. Then disconnect the power cables and then loosen hex bolts on each side of the thruster. Tie a strap around rear of motor housing and tie it around the rails at stern. just snug it up to support it while removing the hex bolts the remaining way. Once the bolts are out you can just slide the unit off the shaft and lift it out. When you are done with repairs getting it on requires lining up the shear pin with the shaft and then slipping the unit on. I fabricated short studs and screwed them in so as to align the unit and supporting it again with the strap. Once it is set in place remove one stud and insert hex bolt and snug it up and then do the same with the next bolt. Once both bolts are tightened remove strap. Hook up power and have a cool beer.
 
I was tracing why my stern thruster failed. Rain water is running down from the area near the stern cup holder and the seat and it then routes around the apex of a bend in the fibreglass just above the stern thruster where it then drips onto the thruster and runs directly into the connection where the control cable enters the thruster.

I actually think a piece of plastic that stops the drips onto the top of the thruster would stop a bunch of the failures.
 
Thanks all, for your kind help. Alice J, am I reading you correct in that it "might" be better to just buy a new motor (or did you mean the entire thruster assy?), rather than play around rebuilding the motor? Knotflying, your directions on removing the thruster assy was exactly what I needed. And Cutwater28GG good tips on hunting down where the water is getting in.
Not sure if I'm going to tackle the Thruster repair/replacement soon, might trailer Scooter out to Calif and West Coast late Spring/Summer, and then address the problem next fall. Procrastination is my middle name! At any rate I'll report under this subject line when I do pull the thruster and diagnose the problem.
 
I removed my stern thruster motor to change the shear pin..not an easy task, but simple steps and allot of elbow grease will get it done..I removed it while my C26 is in the water..so, needing to replace one of the bolts(long story) I have not re-installed the motor yet..Can I drive the boat under-power without the motor attached until re-install?..i.e. will water start gushing in or is it sealed enough with mounting plates??? Thanks
 
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