Trolling power supply question (12v or 24v lower assembly unit replacement)

[Crevis18]

I inherited a boat from my father-in-law (my first boat). It's a 1994 Procraft V180C fish and ski. It has a Motorguide Brute 750 (12/24V) trolling motor system with a steering pedal that has the 12/24V switch. Well, the lower assembly unit with the propeller is bad. I checked the voltage input into the motor with a multimeter, and I can have 12v or 24v. To check the different speed, I attached on the motor terminals two 12v DC light bulbs in series to check the potentiometer...which works fine. Steering is working just fine as well, so the only thing bad is the lower assembly unit. I cannot find the serial number for the motorguide, but I narrowed it down to two different lower assembly units to buy. I am looking at part#: M899701T (12V 5/2 speed @ 54#) and 879345T85 (24V 5 speed @ 75#). The thread pitch has on the shaft is 1-20 and for the propeller nut is .375-24 (checked it myself)....and both parts should fit my system.

My main questions are:
1. What does the 5/2 speed mean (for M899701T)? Is it 5 speed with 2 different voltages (12/24v) setup, or could it be compatible with a 5 speed or a 2 speed setup?

2. Should I get a 12V motor or a 24V motor? Since I can toggle between 12/24V, would I do more damage with supplying 12V to a 24V motor or more damage with supplying 24V to a 12V motor?

3. Is there such thing as too much #thrust? I am new to boating, and everything I read so far says you cannot have too much thrust....is that true?

4. I am looking only having to replace the lower assembly unit, and I will be able to install it all myself, so it would be about $200-$250 to have a brand new lower assembly unit. Should I just not worry about it and get a new one, or should I replace the lower assembly, learn how to use it, and sell it for about $75 when it's time to upgrade?


Thank you for all the inputs or recommendations.

 

[dwco5051]

Not familiar with that motor but will try to help.

3. Easy answer is no such thing as too much thrust. Your motor is listed at 45# which should be adequate for that boat. No matter how big your motor is you will probably encounter a strong enough wind someday to wish you had more.

1. I will assume that 5/2 means 5 speeds on both 12 and 24 volts.

2. Feeding 24 v to a 12 v motor could cause damage.

4. I think the original motor assembly is Mercury 19775A41. Not sure but assuming your motor is a 1994. Matching a different motor may or may not work as it may not be compatible with the present control.

How long since the motor was last useed? Did it work then? Did you check for continuity with the motor leads? It might just need brushes.

Years ago I got given to me a motor that would not run and had sat in a buddy's garage for years. He said it ran when he last used it. I got it back to life by spinning the shaft with an electrical drill an tapping the casing at the same time.

Just general ideas to help lead you in the right direction before spending any money on it.

MOTOR ASSEMBLY, COMPLETE (T45) 19775A41

 

[Crevis18]

Not familiar with that motor but will try to help.

3. Easy answer is no such thing as too much thrust. Your motor is listed at 45# which should be adequate for that boat. No matter how big your motor is you will probably encounter a strong enough wind someday to wish you had more.

1. I will assume that 5/2 means 5 speeds on both 12 and 24 volts.

2. Feeding 24 v to a 12 v motor could cause damage.

4. I think the original motor assembly is Mercury 19775A41. Not sure but assuming your motor is a 1994. Matching a different motor may or may not work as it may not be compatible with the present control.

How long since the motor was last useed? Did it work then? Did you check for continuity with the motor leads? It might just need brushes.

Years ago I got given to me a motor that would not run and had sat in a buddy's garage for years. He said it ran when he last used it. I got it back to life by spinning the shaft with an electrical drill an tapping the casing at the same time.

Just general ideas to help lead you in the right direction before spending any money on it.

MOTOR ASSEMBLY, COMPLETE (T45) 19775A41

Thank you for your input. I actually took it all apart except for the pedal, but before I open the lower assembly unit, I rotated the propeller. It felt like something was grinding. Looks like some of the seals broke. My father-in-law was a truck driver and lost interest in fishing decades ago, so he rarely used the trolling motor....he used the boat mainly for skiing with his family on the rare chance he made it back home in the middle of summer. Otherwise, it stayed outside in the hot sun, and the boat covers constantly broke. The trolling got exposed to the hot sun and weathering elements for the past few decades with hardly any use. Anyways, when I opened the lower assembly unit, it had so much rust in it, and the circuit board in it literally could disintegrate in my hand.

I didn't see the option of boats.net doing a search by year with trolling motors. I looked and compared, since I took it apart, I know the detailed differences. Thank you so much. Mine is very close to the 1995 9HV520JRU. Looks like that the M899701T is a compatible lower assembly unit. Thank you so much for helping me out. I do feel much more confident in restoring it.

 

[MRS]

If motor only 45# it is 12 volt you will burn it up with 24#. Never heard of a motor you can run either or?

 

[Faztbullet]

Save your money and chuck it in recycle bin. You can get a higher thrust model used off CL or Facebook market. Also MRS they have been making 12/24 trolling motors for years. Byrd was one of the first....

Minn Kota 80lb thrust trolling motor - boat parts - by owner -...

Minn Kota trolling motor with 80 lbs thrust! Works perfectly, was just too big for what I need it for. 350 obo. If interested then email me and I will get back with you! Thank you

nashville.craigslist.org