I recently had my Cobra 3520 bounce off of the pavement on it's way to hiding in the weeds and it appears that the shaft has been pushed in a bit.    Having never done this on one of these motors, is there any precautions I need to take before seating it on it's front bearings and "pounding" it back into it's proper position.    I assume that you don't heat the case like it was IC.          The motor runs OK and the shaft is not bent.

Also, does anybody know where to get a 4 hole prop adapter for the 3520?  I find it really strange that they use a 4 hole can and give you a 3 hole adapter.  Maybe they are subtly encouraging you to use a front mount?  I understand that they were originally 3 hole but...damn.

Ken

Ken,
Use an arbor press or a drill press to press it back to position. Is the clip still in the front? Also don’t forget to put locktite on the set screws.
The early version had 3 hole and the newer version went to 4. You can get them from Cobra. If not I have one I can send you.
Thanks
Joe

Thanks - that is what I was hoping to hear.  I have a message in to Cobra so I doubt that I will need yours but thanks for the offer.  The clip is still there.  You mentioned the set "screws"  The only place I have for a set screw is on the rear exposure of the shaft.  Is there another one I am missing?  Have you ever added a support for the rear bearing?  I want to try.  I have a rather slim nose and I really worry about ramp up torque over time.  I think a "sway bar" in the rear would really help.  I see two ways that can be done.  I could remove the set screw from the keeper and let it be the race or build a race around the keeper or just leave it alone because that is a bad idea.  Unbelievable power in these tiny motors!

Thanks Again - Ken

Ken,
The set screws are on the back of the motor if you front mount them.  (the black end!, not the green end!) there should be 2 90 degrees apart. The shaft has machined flats on it that line up with the holes.
Hope that helps
Joe

Ken,
You are right, I had to go downstairs and look. The newer version has only one set screw. The older version has two. See pictures.
PS there should be a screw in there or the shaft will come out! Don’t ask how I know.

 No the prop adapter doesn’t have a set screw. You still need to have a set screw in the houseing to hold the shaft to the housing or it will certainly come apart. I use mostly front mounted. So I really do not have a lot of experience with them.  I do have a few rear mounted ones and didn’t use additional bearings and have not had issues. I prefer front mounted. I have had really good luck with it. In fact I have not had many motor issues either way I mounted them. There are many ways to skin this cat!
Hope that helps
Joe