Maxi-jet Mod chattering!

[scottwhitson]

I just purchased two maxi-jets and did the sure flow mod on them. One of them chattters ALOT! It will run for a little while and then just starts chattering non-stop. The other one chatters as well but not as often. I am new to the maxi mods and am wondering if there is something I can do to make them stop chattering?

[scottbeth]

From most of the reviews that I've read, vibration is a big problem with the MODS, often to the point of it shooting the impeller out the back of the powerhead. However this usually doesn't happen until it's in use for a few months. Make sure it's together securely and clean, otherwise I'd exchange it. ---Scott

[scottwhitson]

It isn't a vibration. When they do it the prop is bouncing in and out against the front cap.

[rick s]

You have to rotate the shroud until you find the spot where they don't chatter when they start up.

Take them out of the tank, put one in a bucket of water, plug in-unplug-plug in, rotating the shroud a little each time until you can repeatedly turn them on without chattering. When you find that sweet spot, take a knife and cut a small groove in the shroud and pump so you'll know where to line them up the next time you take them apart to clean them.

After that, one of mine will start to chatter when it gets dirty.

[scottwhitson]

They don't chatter at start up only after they have been running for a while. I emailed algaefree and will see what they say. I think that there is something wrong with the prop.

[ulua56]

I have been using a Maxi 900 with the small prop(Sure Flow mod 1600) for the last 6 months, I have it on a timer it turns on and off every 30 and 60 minutes.
What Maxijet are you using MJ 900 or 1200 ? Large prop is for the 1200 only.

[scottwhitson]

They are the MJ1200's. I switched it to the small prop for now and it hasn't chattered once. I think that there is something wrong with the large prop. I am waiting to hear back from Sure Flow.

[ulua56]

yup, I was told at the LFS if that happened to sand down the blades on the large prop. I use the 900's, so no need.

[impur]

Mine do that chattering with the white prop too. You have to cut it down a bit.

I made a bunch of DIY mods with the white dumas prop too and they also had to be cut down.

[scottwhitson]

I got an email back already from Algae Free and they are going to send new props to try. If they do it as well then I will have to try sanding them down.