MJ Mod stopped working right...

[tbasinger]

I got a mod kit for my maxijet 900 from mjmods last week. Got it together without a problem, never made a noise or anything. But last night I turned it off to move it and now when I start it up it just rattles and doesn't look like the prop is spinning. If I take it out of the water it works fine, and if I stick it in the water with a little of the shroud sticking out so it can suck water it works, but it doesn't work under water. Anyone have any idea why it doesn't work?

Thanks

Taylor

 

[pitogo]

Re: MJ Mod stopped working right...

<a href=showthread.php?s=&postid=9999451#post9999451 target=_blank>Originally posted</a> by tbasinger
I got a mod kit for my maxijet 900 from mjmods last week. Got it together without a problem, never made a noise or anything. But last night I turned it off to move it and now when I start it up it just rattles and doesn't look like the prop is spinning. If I take it out of the water it works fine, and if I stick it in the water with a little of the shroud sticking out so it can suck water it works, but it doesn't work under water. Anyone have any idea why it doesn't work?

Thanks

Taylor

You using the high flow or medium flow propeller? If its the high flow it may be too big for the 900 to turn.

I am using the 900 with the medium flow prop glued onto a small piece of carbon fiber tube. The tube with the prop is then attached to the mj magnet assembly without the impeller using airline tubing as the coupler. I find the old method much quieter and smoother since it is well balanced. I tried the new mod where the plastic is cut from the magnet and the tube inserted its not very well balanced since the magnet has an oval inside shape and makes the whole assembly wobble.

 

[tbasinger]

I have the medium kit. I used the new method and didn't have an problems with it. Now it just rattles and doesn't flow any water, looks like the prop is just spinning back and forth.

 

[Rhodesholar]

Sounds like the prop is right on threshold of being to big for the pump to turn it. You can either trim down the prop a bit, or get it running out of the water and then slowly drop it in which is always a flood fest. That is what I have to do with my DIY mod.

Also make sure the impeller magnet and inside of the pump are not calcified.

 

[tbasinger]

I might try trimming the prop down, I did try running out of the water and then stick it in there, but as soon as it couldn't suck air it started rattling and stopped pumping water, I just find it strange it worked fine for a week and then nothing.

 

[Rhodesholar]

Again are you sure the impeller is not calcified? That will really cause some headaches. Case and point. My return pump (Genx PCX 55) kept loosing prime and would stop pumping yet keep turning. I took it apart and it was calcified to the point I could not turn the impeller. Cleaned her up and she works like a charm.

 

[tbasinger]

Well the kit was new as of Saturday and still looks new, will give it an other once over.

 

[Bebo77]

try asking in the mjmod forum.. snarky may be able to help you...

 

[jacmyoung]

Your prop is right at the threshold of the motor's capacity. It happens quite often the pump would work for a few days and will start to choke.

Trim down the prop until it will work reliably. The flow will not be reduced because when the motor is in over-drive, the flow does not go up while the motor's watt draw shoots up. This is also not good for the motor in the long run.

And get a kill-a-watt meter to plug the pump in. You will know how much watt the pump draws in real time, and if the watt reading starts to go up that means you need to clean the pump.

 

[tbasinger]

Alrighty, I cut the prop down and it is working now, I think the flow is cut down some but not much, but I really think it was to much in my 46BF.

Thanks again for the help.

Taylor