Why is my MJ1200 with SureFlow mod doing this?

[Delphinus]

You'd almost think it wouldn't matter if the prop was upsidedown on the shaft though, since if its sucking water instead of pushing, it will pull out and hit the tab.

If it's happening every few minutes and the shaft is OK .. hmmm. I've never used the big props, mine are older and from the time they didn't give you the two. So I don't know if it's just something to do with the bigger one .. but it seems to me if it's hitting the tab and switching directions ... then hitting the tab again a few minutes later, then it must have switched directions in that time. Dodgy electricals? It's not running on a wavemaker is it (seems like an obvious question but I'll ask it anyhow).

(And if so, I found they really don't last when on wavemakers. Everytime they startup, there's a little vibration in the whole unit. This eventually distresses the little holder-arm thing that attaches the powerhead to the glass magnet, and it breaks at the socket point. I tried all manners of fixing it, but basically once this is gone, it's gone, nothing I could think of would keep it fixed longer than a week or so.)

[fkshiu]

The propellor is spinning the wrong way and is hitting the tab which is designed to make it spin the correct direction. What is probably happening to prevent this is the greater interial mass of the white (bigger) propellor is preventing the proper bounce back. The smaller (black) propellor does not have this problem on Sureflow kits. All the snapping against the tab puts extreme torque on the propellor which will eventually tear it apart. This is why you should NOT use these things on a wavemaker.

How do I know this? Numerous tries on building my own "maxi-streams" out of various bits and pieces before there were DIY kits available along with reading the monstrous thread on RC. The bottom line is that if you get too greedy and push the envelope (i.e. the bigger white propellor on a Maxijet 1200) you're going to run into trouble. Remember, this is - after all - a DIY project. One of my Franken-streams is now the dedicated salt mixer - a job it excels at but makes a big racket doing.

If you stay conservative and use the smaller black prop on a Maxijet 900 it shouldn't give you any problems. I've had my Sureflow going without issues for over a year now.

[mike31154]

Originally Posted by Delphinus

You'd almost think it wouldn't matter if the prop was upsidedown on the shaft though, since if its sucking water instead of pushing, it will pull out and hit the tab.

If it's happening every few minutes and the shaft is OK .. hmmm. I've never used the big props, mine are older and from the time they didn't give you the two. So I don't know if it's just something to do with the bigger one .. but it seems to me if it's hitting the tab and switching directions ... then hitting the tab again a few minutes later, then it must have switched directions in that time. Dodgy electricals? It's not running on a wavemaker is it (seems like an obvious question but I'll ask it anyhow).

I thought maybe an electrical problem as well, since once it hits the tab on initial start up and then starts spinning in the desired direction, it should continue to run smoothly until power is cut off and it is restarted. Myka did mention that it seems to be running in the wrong direction though. If the prop is mounted upside down, perhaps the curvature prevents it from properly engaging the kicker tab???