Starter motor / Powder coating?

Starter motor / Powder coating?

I would like to powder coat the steel barrel (stator) but I am concerned about the magnets.

Anyone know if the magnets are held in place by magnetic attraction to the steel tube or is there some type of adhesive also involved. I do not want to expose the part to powder curing temperatures (450f) if it will damage the magnets or adhesive if used and I don’t want to force the magnets out of the steel barrel if there is an adhesive holding them in.

FlyGp

 

I believe they're bonded in place in some fashion; I don't think they were trusting just the magnetic attraction.

As out of the way as the starter motor is, powder coat the end cap and then spray the body. If you use Duplicolor gloss black brake and caliper paint or engine enamel and let it properly cure, it'll be almost as tough as powder coating.

That's what I plan to do, myself.

 

Fitz

the reason bonding even occurred to me is that there is a stain as if the magnet was placed in the tube and slid towards the end with the locating / stop tab leaving some bonding material on the tube surface.
Other than that the starter I have has no glue evidence / squeeze-out around the magnet edges.

Have you used Duplicolor engine paint before? I am trying to decide on POR-15, Eastwood ceramic with activator, or Duplicolor.

FlyGP

 

i got a kz550 cheap once because one of those magnets came unglued. a propane torch on the housing loosened the other one with no obvious damage, used Gorilla glue to reattach.
if you take them out, mark them so they go back in the same way

 

Don't paint anything that lives under the carbs.

 

But Wiz isn’t it painted now? The one I have is a light gray or silver and acetone takes the factory finish right off. In the photo the dark splotch under the tag has been cleaned with acetone.





FlyGp

 

It's paint.

I use Duplicolor 500* engine enamel all the time; and it's tough as nails once properly cured. A quick gasoline spill won't touch it (although I'm sure an extended drip-drip-drip might.) But is HAS to be fully cured; it has to pass the "sniff" test. (Stick your nose against the part and sniff; if it smells AT ALL of paint, it's not cured yet.) This can often take as long as two weeks. I've used it to repaint my jugs, valve cover, wheels, and an assortment of brackets, covers, etc. I like it because it comes in gloss, "low-gloss" and flat, and for rattle-can paint, it's really durable. Chain lube won't even damage it, ONCE IT'S FULLY CURED. It also needs to be applied according to instructions paying attention to the "re-coating window" guidelines on the can.

 

Back to the OP - I have a starter motor (XJ550) apart at the moment - I was considering a conversion they do on the ventures to improve the earth and so had taken apart a spare one, but the brushes are worn down, so it's hardly worth bothering.

Anyway - I went to have a look at the magnets for you and found one of them had broken in half (well one thrd and two thirds, but two pieces anyway) ! Hopefully I would have noticed before I had re-used it...

Nevertheless, the magnet-and-a-bit that are left seem to be securely bonded to the outside, whereas the broken bit can be moved around quite easily, although there's not much trace of any adhesive that I can see.

 

Whatever you end up doing be advised that powder coat does not conduct electricity. You want to clean any off grounding surfaces or you'll have a problem.

 

You do know that once a magnet breaks in half you get [N/S/N/S] where you once had [N/S] and the magnet is ruined and unrepairable??

Just clarifying the point.

 

If the parts mate up then there should be no effect on the field they produce, you could think of a stack of magnets as a large single one. Having said that, it's not the only one I have lying around and some fault must have broken it. I might have re-used it if I had been desperate, but I'm not...

 

So tell us, were they "glued in" at least at one time?

 

Sorry to disagree - if you were picking up screws, there would be no problem.
But - the electric motor field both pulls and pushes, and a broken magnet just won't do. It ruins the effect.

A broken magnet is a broken magnet, even pushed together or glued.

 

I just wanna confirm that they're glued in to begin with...

 

Sounds like the magnets may be brittle; I think I will just keep them attached to the steel tube wall.

Fitz do you cure the Duplicolor high temp paint in an oven, thought I read somewhere that you cure the engine enamel at 200f.

Gold info / observations guys thanks for the comments.

FlyGp

 

Fitz, the ones on that Kawasaki were, i would think they all are. when i had the seca starter apart i dripped super glue between the magnet and the housing just to make sure

 

Sorry - missed the question.

The magnets certainly appear to be glued in, but I didn't prise them out to check. There was no bulky glue though, so after 30 years of being attached they might simply have liked being there ! Probably glued though. If you need to know I could try chiselling out the broken magnet though.

With so many bits of starter motor lying around I decided to do a mod familiar to Venture/V-max owners of improving the earth connection. On those it involves connecting an earth strap from the brush plate to a threaded hole in the aluminium housing. The XJ body is steel, so I welded a spot and filed it flat. I don't think I'd recommend it for everybody (unless they're confident welding and have sufficient spares to allow for mistakes) but it does seem to have made the starter spin more easily. Mind you, for a 'fair test' I would have tried it with the old brushes, rather than changing for a less worn set, but that's another story.