Unique Magnum 350 problem...

Kindoflikebilly

Feeder Fish
MFK Member
Oct 4, 2011
5
0
0
Brooklyn, NY
So, I've used the same Magnum 350 unit for 5-6 years and just recently had a canister failure. The magnet rusted out, likely due to years of abrasion of grit between it and the canister, eventually causing a crack in the canister. I bought a new canister, magnet, and impeller. (My o-rings seem fine and I have a good seal. All hoses are clear and the quick shut-off valves are open.) When I set everything up, the impeller just vibrates and doesn't actually spin. It's like the motor just doesn't have enough ummph to get the impeller to "turn over" and start.

I tested the system in the tub: motor and canister with filter pad-wrapped media container in place but top off. I could only get the impeller to spin if the canister was half full. It would continue spinning as I added water, but just won't start with a full canister of water.

Does the new magnet not match the old motor? Is there any way to force water through the system when hooked up to get the impeller spinning??

Thanks much in advance for any advice.....
 

stingraybob

Feeder Fish
MFK Member
Feb 17, 2009
324
1
0
Toledo,OH
What happens if you let it go for a little bit? does it sound like its spinning? does it sound like it wants to spin and its just knockin off the sides of the motor? check your impellar and make sure the impellar itself is attached to the shaft...spin it in your hand and make sure it all spins together...i had that same issue with a powerhead once and it was the impellar came apart from the shaft...i just epoxied the impellar to the shaft and its been workin about 3 years now that way
 

KaiserSousay

Feeder Fish
MFK Member
Feb 20, 2009
1,230
0
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PartlyCloudyFlorida
Something is binding.
Give Marineland a shout. They have a very good customer service group.

Not sure what kind of filter that has the impeller fixed to the shaft, but is not a Magnum.
Impeller has to spin freely on the shaft.
Shaft is held at top and bottom.
If you epoxy shaft and impeller, you end up with a tiny paper weight.
 

jdhuegel1

Gambusia
MFK Member
Sep 30, 2011
297
3
16
Frederick MD
Sounds like your motor may be done; however, take the canister off and pull out the impeller. Make sure the impeller 'grabs' the shaft when you spin it. If you can spin the impeller around and the shaft/magnet stay still, just replace the impeller assembly.

Let me know if that does/doesn't make sense.
 

WckedMidas

Fire Eel
MFK Member
Mar 31, 2005
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stingraybob

Feeder Fish
MFK Member
Feb 17, 2009
324
1
0
Toledo,OH
Something is binding.
Give Marineland a shout. They have a very good customer service group.

Not sure what kind of filter that has the impeller fixed to the shaft, but is not a Magnum.
Impeller has to spin freely on the shaft.
Shaft is held at top and bottom.
If you epoxy shaft and impeller, you end up with a tiny paper weight.
If I didnt set my 350 up on my moms tank Id show you what I was talking about when I said I epoxied it to the shaft...If you saw it you would say ohhhh gotcha lol
 

KaiserSousay

Feeder Fish
MFK Member
Feb 20, 2009
1,230
0
0
PartlyCloudyFlorida
If I didnt set my 350 up on my moms tank Id show you what I was talking about when I said I epoxied it to the shaft...If you saw it you would say ohhhh gotcha lol

I`m gonna guess you glued the impeller vanes to the magnet.
 

Kindoflikebilly

Feeder Fish
MFK Member
Oct 4, 2011
5
0
0
Brooklyn, NY
Sounds like your motor may be done; however, take the canister off and pull out the impeller. Make sure the impeller 'grabs' the shaft when you spin it. If you can spin the impeller around and the shaft/magnet stay still, just replace the impeller assembly.

Let me know if that does/doesn't make sense.
When I received the new magnet and impeller assembly, I removed (and later replaced) the lower rubber bumber to slide the magnet onto the shaft. I then clicked the magnet to the actual impeller, so the impeller and magnet cannot move independently. However, there is about a 1/8 turn of play between them. (i.e. holding the impeller, I can rotate the magnet about 1/8 turn until it stops.) But I am pretty sure this is always how it was. I don't think gluing the two together will alter much other than to remove that play.

As I mentioned, the new assembly does work, just not when having to move a full load of water. I think when I try again today, I will attach the canister to the tank mostly without water, turn it on, and hopefully get the impeller spinning. Then, I'll slowly open the quick-release valves and allow the canister to fill. I'll keep my fingers crossed that the pressure of the water won't overcome the force of the magnet.

I'll report back on how it goes. After 5 years of really no problems, this is super frustrating.

Thanks for the help, though!
 

stingraybob

Feeder Fish
MFK Member
Feb 17, 2009
324
1
0
Toledo,OH
Thats def interesting...wonder if the motor just doesnt have the arse to spin it once its under a load...interested to hear a solution or cause to the problem
 

KaiserSousay

Feeder Fish
MFK Member
Feb 20, 2009
1,230
0
0
PartlyCloudyFlorida
Just a thought.
Have you tried to run it with the media cage only, no media in it?

Guess you have checked your hose set ups and found no obstructions.

Don`t think your motor is bad.
They either work right or not at all.

I would try setting up in the garage with a bucket of water.
Put the intake in the bucket and suck on the return line.
If you can get a siphion without it running your system should run.
Maybe while you have a siphion running, plug it in.
See what happens.
 
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