R75/5 Charging issues

[anotherbmw]

Guenther, see photo attached. Only 4 Ohms between the post and the stator frame (Voltmeter set to 200 Ohms)! Brushes are not connected to the rotor, because I put some cardboard in between the brushes and the rotor. This tells me I better should not connect the plus cable from the battery there at this point.

Boxerbruce, when I started trouble shooting on Friday I called EME at 5:00 p.m and they were very helpful, one of the guys even gave me his cell to call him over the weekend. I didn't do that, wanted to first try myself (with y'alls help )

Steven, I am pretty sure I have assembled things correctly, but what do I know!

Brook, I love your write-ups and videos. They are an amazing source of information! At this point I am pretty sure my problem is what you list under 7.) below. I will take the stator frame and stator off and take a look. Whatever I find I will report back.

Cheers!

 

[stevenrankin]

Thank you Brook

Hey Brook, Nice write up.

Now I know what the by pass gizmo is for. Filed away in the sieve.

I had thought about the terminals on the alternator, IF the insulators are not put back in the correct order, things won't work. I was going to suggest checking them for that problem.

I hate to say it because I don't want to sound like a jerk but, something is not assembled correctly. As Brook says, a wire on the wrong plug, or a missing insulator is more likely the cause than a defective part.

I am not throwing rocks here. I am one for putting things back together and finding extra parts, or shuffled wires myself. I just did some work on my carbs and after I had everything back together and was letting the lift down, I spotted one of the atomizers lying on the floor under the lift. Needless to say, I had to take them partly apart to fix my mistake.

Follow Brook's advices, can't go wrong. St.

 

[brook.reams]

Guenther, see photo attached. Only 4 Ohms between the post and the stator frame (Voltmeter set to 200 Ohms)! Brushes are not connected to the rotor, because I put some cardboard in between the brushes and the rotor. This tells me I better should not connect the plus cable from the battery there at this point.

Boxerbruce, when I started trouble shooting on Friday I called EME at 5:00 p.m and they were very helpful, one of the guys even gave me his cell to call him over the weekend. I didn't do that, wanted to first try myself (with y'alls help )

Steven, I am pretty sure I have assembled things correctly, but what do I know!

Brook, I love your write-ups and videos. They are an amazing source of information! At this point I am pretty sure my problem is what you list under 7.) below. I will take the stator frame and stator off and take a look. Whatever I find I will report back.

Cheers!

Hi Olaf,

Yes, I think the problem is that the (DF) terminal is not insulated. With the (DF) and (D-) brush wires removed from the brush terminals, you should see infinite ohms between the (DF) terminal and the stator case, but you are seeing a low resistance path.

I think you are on the path to problem identification and resolution.

Best.
Brook Reams.

 

[brook.reams]

Hey Brook, Nice write up.

Now I know what the by pass gizmo is for. Filed away in the sieve.

I had thought about the terminals on the alternator, IF the insulators are not put back in the correct order, things won't work. I was going to suggest checking them for that problem.

I hate to say it because I don't want to sound like a jerk but, something is not assembled correctly. As Brook says, a wire on the wrong plug, or a missing insulator is more likely the cause than a defective part.

I am not throwing rocks here. I am one for putting things back together and finding extra parts, or shuffled wires myself. I just did some work on my carbs and after I had everything back together and was letting the lift down, I spotted one of the atomizers lying on the floor under the lift. Needless to say, I had to take them partly apart to fix my mistake.

Follow Brook's advices, can't go wrong. St.

Steve,

Yes, you remind me of a recent embarrassment when I was installing the top end on the 1977 R100RS rebuild project a couple years ago. I was all done and began cleaning up my workbench, when what to my wondrous eyes did I spy: a large O-ring which goes on the cylinder base. "That's not supposed to be there!!!!" I picked up a new head gasket (they are use once IMHO after the head is torqued) and got some "additional practice" installing top ends.

Best.
Brook Reams.

 

[stevenrankin]

One day

I will tell you the story of my friend pouring oil into the timing hole. (he didn't have his glasses on and the plug was out). We had just done the rear main seal. It was not until we pulled everything back down to the bare seal only to find it intact did I notice the oil around the timing hole. St.

 

[guenner]

This tells me I better should not connect the plus cable from the battery there at this point.

13V/4ohm=3.25A - not even enough to warm up that wire.

Good thinking!

/Guenther

 

[anotherbmw]

Check this out!

With stator removed I get 1.3 Ohms from the supposedly insulated post to the stator cover (Pic 1).

I then removed the brush holder. The "ring" on the left in Pic 2, which was partly falling apart, was in there to insulate the bolt from the stator housing. The ring on the right is from my 45 year old stator frame and looks much more promising, so I put that one in.

But as you can see in Pic 3, I still have only a little over 100 Ohms resistance now. Is that sufficient? I would think it should be "indefinite". I measured on my old stator and on my other /5 and both were indefinite. I think I need to talk to the friendly folks at EME next or what do y'all think?

 

[stevenrankin]

Don't worry

I understand the need to be sure everything is proper before putting it all back together again hence, the measuring of resistance and such. This really is important with old parts and troubleshooting. I most certainly do measure things when looking for a problem.

I would say with great certainty your problem has been solved in part now by replacing the bad insulator. UNLESS, you don't have all the insulators in the correct places.

I don't say this to be a jerk, it is one of my problems I am having as I age I MUST take pictures of things every step of the way when taking things apart for repair. I also make sure I have a very good shop manual and parts diagram handy as well. Why? Because I find some times I forget just how little things go back together again. Being methodical and taking pictures saves me a lot of grief.

Having pulled the terminals apart on a stator, I remember one time I went crazy trying to figure out just what order and terminal they went back on. Finally between the parts fiche, and shop manuals, I figured out I had one of the insulting washers on the wrong terminal.

I believe it was a tiny thin one that went on the back side of the stator. It insulates the Head of the bolt on the backside. That terminal (Bolt in reality) has to be fully insulated. I got the bolt head insulator on the other terminal.

So, I think you have narrowed down the area of fault and it will be something very simple. Good luck. St.

 

[guenner]

100 Ohm is not an insulation!

The ring was in the brush holder assembly, right? Didn't the stator cover come with everything assembled and hence a new ring?

100 Ohm is unexpected.

Do the measurement with the 'Y'-stator coil disconnected. Just to make sure there is no open coil wire rubbing against the stator cover.

/Guenther

 

[anotherbmw]

100 Ohm is not an insulation!

The ring was in the brush holder assembly, right? Didn't the stator cover come with everything assembled and hence a new ring?

100 Ohm is unexpected.

Do the measurement with the 'Y'-stator coil disconnected. Just to make sure there is no open coil wire rubbing against the stator cover.

/Guenther

Yes brush holder assembly came mounted on the store cover. I agree that 100 Ohm is not ok. With the Y wire disconnected I measure infinite resistance, so insulation in the Y post is fine.

I called EME today, they admitted that there must be something wrong with the insulation pieces and they put some replacements in the mail. So in a few days I will hopefully be up and running!

 

[anotherbmw]

And thanks everyone for helping me troubleshoot. I may write a book now

 

[stevenrankin]

Don't forget

Don't forget to let us "experts" LOL, know what the problem was.

Just to recap, did you in fact take the terminal insulators apart at one time? Or, did this new part come all assembled? I did not buy from EME I bought from Motoradelectrik. I recall I had to use the original equipment housing and brush holder. Things had to be disassembled to install the new stator. Hence, my mix up with the improper placement of one of the insulator washers. Of course, this would have caused a short or ground, nothing good. I caught it because I just didn't like the way things went together, it didn't make sense the first way I reassembled it. Lucky for me I caught it before I put everything back together and hooked up the battery. Who know what might have happened, LOL.

Good of EME to stand by their product. If in fact it is a flawed new part, I am surprised. They have been selling the kits for quite awhile now and have a good rep. St.

 

[anotherbmw]

All came assembled. Brush holder was in the stator cover. Of course I assumed all was good, so I didn't measure anything before putting it together.
I agree, they were very helpful in resolving this. I will report back in a few days when I get the new insulating bits and pieces.

 

[ebeeby]

I love a happy ending.

 

[stevenrankin]

They should stand by

So, you did not do any assembly or disassembly of the front cover or brush housing. In that case, I will have to say someone at EME's supplier screwed up.

Seems obvious now the insulators were incorrectly installed. Or, if this is a refurbished unit sold to you, someone did not refurbish it properly.

I would expect them to solve the problem.

When I did my charging system update, I had to take the cover and brush housing apart and use my original cover and brush housing. So when I screwed up by not putting the insulator washer under the bolt head It was MY Fault. I am prone to do that sort of thing sometimes. I would expect a unit assembled by someone selling it to me as a new part, would have done the assembly correctly.

Cain't wait to hear the outcome. St.

 

[anotherbmw]

Latest update

So here is where I stand: I received the new insulating pieces from EME, put them in and pronto, all good. It looks to me that when the brush holder was installed (not by me, it came assembled), the inner shaft insulator piece was damaged. At least it looked like it when I took it out.

All is well now, but check the video below, there seems to be quite a bit of wobble in the rotor at idle rpm. You can look at the wires on top of the brushes. Is this normal? It seems that it goes away at higher rpm. Rotor is torqued to spec using a new bolt.

This is a link to my OneDrive, hope that works. And the video is in SloMo, so it may look more dramatic then it really is.
https://1drv.ms/v/s!AsCgxCLhHJ8_g7AlN-IPIkeVG3bopg

 

[pglaves]

So here is where I stand: I received the new insulating pieces from EME, put them in and pronto, all good. It looks to me that when the brush holder was installed (not by me, it came assembled), the inner shaft insulator piece was damaged. At least it looked like it when I took it out.

All is well now, but check the video below, there seems to be quite a bit of wobble in the rotor at idle rpm. You can look at the wires on top of the brushes. Is this normal? It seems that it goes away at higher rpm. Rotor is torqued to spec using a new bolt.

This is a link to my OneDrive, hope that works. And the video is in SloMo, so it may look more dramatic then it really is.
https://1drv.ms/v/s!AsCgxCLhHJ8_g7AlN-IPIkeVG3bopg

Congratulations on the charging issue. But the rotor wobble is troublesome. Step one is to check and verify the mounting of the rotor on the shaft. If that is OK the wobble signals a problem with the crankshaft bearing. Not a good sign.

 

[1074]

Congratulations on the charging issue. But the rotor wobble is troublesome. Step one is to check and verify the mounting of the rotor on the shaft. If that is OK the wobble signals a problem with the crankshaft bearing. Not a good sign.

+1

 

[stevenrankin]

Thank you for telling us

Thanks for telling us the solution to the original problem.

I hate to think the rotor may not be properly made as to not mount straight on the shaft. Paul, has the only other likely explanations.

How many miles do you have on the bike, Not many would give me doubt the bearing is shot. Lots would.

Please let us know what you find out and you have my sympathy for the recurring problems. St.

 

[guenner]

Maybe there is something wrong with the bolt. Is this bolt new?

/Guenther