help with stupid mj mod question


Premium Member
hello,im attempting to build the first of 2 mj 900 mods and im really having a hard time.Im sure its an easy build once you've done one. The kits didn't come with instructions but they do direct you to go to an RC thread where someone was nice enough to take the time and take pics of their build.Well I must say that Im still having trouble with it.
So I have everything built and when i try to put the impeller into the motor and shroud it seems like the stainless steel shaft is like 1/4" too long.The instructions dont mention me having to cut this shaft down.
Can anyone help???:(


New member
The stainless rod is supposed to stick out about 1/4" out of the assembled prop on either side (so about 1/2" total). The rubber like red/black thingamajigs go on either end and then the one in the prop end fits in the centering cap on the shroud.


New member
You might also not be getting the shaft seated down in to the "rubber thingamajig" properly. Make sure to look inside the MJ and see that you do have the red and black stopper that came with the MJ originally. You do need to re-use these.

Hope that helps.



Active member
I had to grind a little off one on the SS shafts. At first I thought it was just the burrs that were keeping the end caps from seating all the way. At the original length the shroud and centering cap wouldn't stay seated.



In Memoriam
It's a DIY project so don't be afraid or surprised that you have to do a bit of cutting here and there still :)


Premium Member
Thanks everyone who answered my cries for help. Last night I double checked to see if I can push those red and black stoppers on farther and I could but it still isn't enough.I may have to shave down the stainless steel shaft like 1/16" or so. I wish I knew if the shafts that are included in each kits are always exactly the same length.
thanks again