Who's replaced brushes on Bosch starter?

[Ray from Indiana]

I've been asking around on this one and I'm getting mixed answers. Hopefully somebody that's actually done this on their airhead starter can help me out.

I decided to freshen up my starter - replace commutator bushings and replace brushes. No, I'm not messing with the Bendix bushes - they're ok anyway.

My objective is to do this once and not mess up so as to make the starter unreliable.

The original brushes were spot welded on both the brush plate and the armatures. I ground off the the old braided leads from the connection points. I was going to solder the new brushes on with 50/50 solder but some have told me the amperage can melt it off. Don't want that do we?

I don't have access to a spot welder. Silver solder was suggested but I worry about applying the amount of flame to the thin armature connection point. I guess silver solder would be easy for me to make connections at the brush plate for the commutator. Another option I guess would be to devise a crimp around the brush lead and the armature connection then try to solder that but again I worry about silver soldering the thin armature connection point.

What have others done????? No, I won't be going to an automotive starter rebuilder - I just want to do it myself and looking for the best method. I've received some advice from others but I don't think any of them have actually done this job before

thanks

Ray

[Kurt in S.A.]

This website says "just a bit of soldering" is needed:

http://www.thisoldtractor.com/gtbender/ ... bosch-.htm

Kurt in S.A.

[Ray from Indiana]

Yeah I know.

[Ken in Oklahoma]

I too don't know the answer. I too would be nervous about soldering the leads, but from a little different standpoint. My concern is that the solder would wick it's way along the braid and create a sharp transition from the solder to the braid proper. If the braid vibrates, whether when operating the starter motor or not, I can visualize a vibration "focusing" at the solder/copper junction. The braid would be likely to flex and fatigue right there. I believe the original welded connection would be more forgiving.



Ken

[Ray from Indiana]

Will be easy to prevent wicking solder. Just tin both parts and position solder parts to work with gravity then use hemostats or needle nose pliers to be a heat sink on the braid near teh connection point.

My problem is solder, silver solder, crimp, or crimp and solder. If solder what blend Bb/Sn

The field coil brush connections are the ones that makes me nervous

[Kurt in S.A.]

Snowbum mentions soldering the terminals...needs a hot iron...I suspect to get the local area hot quickly without leaving the iron in place for too long for the heat to migrate. Bob grew up with electronics, so if you have some experience as well, I suspect it should be no problem.

http://bmwmotorcycletech.info/boschvaleostarter.htm

Kurt in S.A.

[Jean]

I took mine to an auto-rebuilder who specialized in rebuilding old (Beetle) VW starters.
(A little shop-in-the-woods sort of place)

[Ray from Indiana]

After getting advice from several Moto Guzzi and airhead people that have actually replaced the brushes using solderand having the starter still operate reliably, I'll just solder the new brushes in.

Here was my area of concern. It was soldering the field coil connections.

Look at picture # 27 here.
http://www.thisoldtractor.com/gtbender/ ... bosch-.htm

You'll notice how the field coil connection on this starter has a vertical tab and apparently a hole through it that the brush lead went through then its soldered. This must be a much earlier model starter than mine which is still a #157 starter but mine had spot welded connections and no vertical tab.
Interesting too that this earlier starter had soldered connections.

Here's pics of my field coil connection point after old brush removal .



The older versions starter would be easier to replace brushes. That's why Greg Bender's note says "just a bit of soldering required".

You can also see why I wouldn't want to generate enough heat at this point to silver solder. Yes, I did cross post this issue but more heads are better than one.

[Jean]

Ray, what year bike is your starter on?
So we'll have some sort of clue when they changed from solder to spot welding...

[Ray from Indiana]

Its an 82 R100

Starter was getting sluggish even with very good battery conditions....found a cracked brush and nose bushing pretty well worn