Bow Thruster

[Lom]

I have a '98 350 with a Bow-Power belt drive thruster. Anyone familiar with this unit ???, was it original equipment ??? ..... it is next to useless even in a dead calm. Any information would be appreciated.

Lom

 

[Shrew]

Do you have a single or twin engine. Mainship didn't install a bow thruster in the twin engine 350 to my knowledge. This was installed in all of the singles that I've seen.

My 1999 and any other one that I've seen is a Side-Power.

I'm not familiar with that brand. If you have a twin engine, I suspect that is an after-market installation.

 

[Lom]

She's a single screw, I've never come across a belt driven thruster & Bow-power bring nothing up on Goggle
Thanks for the input

 

[Comodave]

Welcome aboard. Can you add a photo or two of the unit?

 

[Jeff F]

Welcome. No insight on that model, but I can say that in my estimation 90% of complaints over thruster performance turn out to be power related rather than thruster related. On a lot of Mainships the bow thruster is powered from the house bank.

My approach would be to figure out where the power is coming from and then do a voltage test at batteries and thruster during a 20 second burst. See what that tells you before tearing into the thruster.

Jeff

 

[BruceK]

Welcome. No insight on that model, but I can say that in my estimation 90% of complaints over thruster performance turn out to be power related rather than thruster related. On a lot of Mainships the bow thruster is powered from the house bank.

My approach would be to figure out where the power is coming from and then do a voltage test at batteries and thruster during a 20 second burst. See what that tells you before tearing into the thruster.

Jeff

Agree. Lacking experience of bowthrusters, I thought mine was undersized an inadequate until I replaced the battery and discovered it was more than up to the task.

 

[Comodave]

I have a '98 350 with a Bow-Power belt drive thruster. Anyone familiar with this unit ???, was it original equipment ??? ..... it is next to useless even in a dead calm. Any information would be appreciated.

Lom

I have no knowledge about this thruster, but in general the first thing to check is electrical connections. They have a way of getting loose and corroded. I would check every connection to make sure it is tight, clean and has a good mechanical connection to the cable. Check the voltage at the battery and again at the thruster under load.

 

[Bmarler]

There was a thread a while back about a member here that had a belt drive thruster. His motor was shot and the company was either gone, or the unit wasn’t supported anymore. But, being belt drive, you can put a variety of motors on it if you find that it’s just too underpowered after checking all the connections and batteries.

 

[J.T kearney]

Hi
I have the same boat and thruster. It was commissioned in Vancouver BC.
Bow power is out of the Seattle area. She also ended up with an Ample power alternator and remote regulator, also out of Seattle.
Does your thruster have a battery under the bed in the state room or like ours, it is connected to the house bank. Ours is a 5 hp and has worked quite well since we went to lifepo. Make sure all connections are clean and tight!!
From what I understand its basically a starter motor with a belt driven component with blades. It's been a good one for use since the lithium up grade, but make sure to check those connections and keep the prop clean. Tacoma Prop where able to give me a small print out on the thruster, you might give the
m a try. The only place I can find zincs for this is Marine Hardware at $40.
All my info is over at the boat (4 hrs away).
Cheers and Happy NewYear
J.T

 

[Islander2017]

I have a Bow Power bow thruster in my Camano Troll. It is the one referred to a couple of posts up from this one. The motor failed on it but I was able to get a replacement for it in Campbell River. The thrusters are no longer made and the company is now called Marine Hardware, in Seattle. I contacted them at "ront@marinehardware.com" Ron tried hard to be helpful but couldn't give me too much information other than the motor he thought was an old ford starter motor. When I installed the new motor I also installed a dedicated battery for the thruster and windlass in the v berth so the cable run was much shorter and the thruster now has a lot more power. Could be the new motor, shorter cable run or a combination of the 2 but the difference is very noticeable. For zincs I'm using a prop zinc which seems to work quite well at a 1/10th of the cost of the one Marine Hardware sells for it. Hope that info helps with the issue.

 

[Lollygag1]

Had the same issue w my side power unit. We upgraded the thruster prop and added a dedicated battery next to the thruster. Result is I have more than enough umph to turn the boat it almost any conditions

 

[J.T kearney]

Islander 2017

can you give a little more info on the zinc you use. I hate spending $40 on zins for these.
Cheers J.T.

 

[J.T kearney]

Also on any info about the starter you replaced. Was it a ford? Was the old one rebuildable?

 

[Shrew]

With most electric motors, but in particular thrusters, the issue is typically:

Voltage drop due to distance or batteries

brushes

corroded connections

 

[Islander2017]

can you give a little more info on the zinc you use. I hate spending $40 on zins for these.
Cheers J.T.

I have a spare on the boat and I'm running down there later today to check on it. I'll get the number and let you know.

The old motor was checked over by 2 different technicians and both said it couldn't be repaired. They both also said it wasn't a ford starter so maybe it wasn't the original. The new one was sourced for me by Penner Automotive and Marine in Campbell River, it's made in the US but it doesn't have a brand name on it so I can't help you there. Hope that helps.

Cheers.

 

[Bmarler]

i wouldn't think they'd use a starter motor for thruster duty. most starter motors are series wound for high starting torque but don't have good speed regulation with variable loads. reversing a series wound motor requires access to the field and armature windings and can be more complicated then simply reversing polarity like a shunt wound motor.
shunt wound motors would run at a constant speed better.
BTW, i'm no engineer...
the belt drive thruster is intriguing to me. you would think almost any motor might adapt to it with some adept bracket work. does anyone have pictures of one of these?

 

[Bmarler]

is it similar to this? https://powerproductsystems.com/7726.html

 

[Islander2017]

is it similar to this? https://powerproductsystems.com/7726.html

yes it's quite similar. This is the old motor.

 

[Islander2017]

can you give a little more info on the zinc you use. I hate spending $40 on zins for these.
Cheers J.T.

Here's the zinc I've been using

 

[J.T kearney]

Ilander2017
I bought a few similar too that but was worried about not getting enough contact with the prop hub or shaft. Do you find normal zinc loss compared to the other zincs on your boat? The replacement zinc from Marine Hardware are at least twice as heavy, pretty robust. When I got the boat the owner used a disk type and would burn up pretty fast. Last thing I need is losing my thruster to corrosion!!
Thanks and Happy New Year
J.T.

 

[Islander2017]

Ilander2017
I bought a few similar too that but was worried about not getting enough contact with the prop hub or shaft. Do you find normal zinc loss compared to the other zincs on your boat? The replacement zinc from Marine Hardware are at least twice as heavy, pretty robust. When I got the boat the owner used a disk type and would burn up pretty fast. Last thing I need is losing my thruster to corrosion!!
Thanks and Happy New Year
J.T.

I find that these last 4 to five months where we are. I was concerned about the contact as well but these are what the previous owner use for 17 years…

 

[J.T kearney]

Islander 2017

Great to know on the zinc life. sounds like it's doing it's job. Is that about what your getting out of your other zincs? My marine hardware zinc will give me a little over 12 months unless someone with a hot boat parks next to me.
Thanks again
J.T.

 

[Islander2017]

It is the shortest lived zinc on my boat. I change the shaft zinc and transom zinc about once a year. The bow thruster isn't bonded and I wonder if that is the reason for the faster erosion.
Cheers.

 

[Bmarler]

It is the shortest lived zinc on my boat. I change the shaft zinc and transom zinc about once a year. The bow thruster isn't bonded and I wonder if that is the reason for the faster erosion.
Cheers.

very likely. you might consider getting someone with a silver half cell down to take some readings.

 

[Islander2017]

Thanks, yes that's a good idea. I have a mechanic scheduled for some work later this month. I'll get him to check that as well.
Cheers.

 

[J.T kearney]

Islander 2017

Its been so long since I check my thruster from inside the boat being it's powered by the house battery. Now I got to take the bed apart to see what's going on with it, connection wise. Definitely taking a few pictures this time.
Great info and thanks again.
Cheers J.T.

PS Don't forget the zinc I'm using is twice the weight of yours so it would last twice as long?

 

[Comodave]

Yes, check the connections for being tight and clean. I sometimes take voltage readings at points along the path to see if there is any significant voltage drop. It is surprising sometimes how much voltage can drop over a bad connection. And thrusters work best with good voltage. Short runs out of heavy cables. I look at the sepcs for the cable size and go larger cables if at all possible. It is a one time cost and benefits are forever every time you use the device.

 

[Lom]

Thanks all for the input. Had to put this project on the back burner, but got back into it. My set up is battery & charger under berth adjacent to thruster motor. Installed new grp. 31 & charger. clean heavy cable & connections. Still not impressed with thrust. Does any one know tunnel dia. on the 350 ??, my theory being if the tunnel is too small, more power won't do much without a larger prop. My unit looks like the photos & diagram shown from others.

Thanks
Lom

 

[Flac203]

Boatzincs.com / Cheap overnight delivery quality zincs