Starter/load shed relay issues

[F14CRAZY]

For the past week my bike, again, has been having issues starting and/or keeping the lights on.

Sometimes, I'll turn the key on and the exterior lights do not come on. Pressing the starter will only trigger the fuel pump. If I put the bike in and gear and rock the engine a little the lights will come on and it'll start.

Then, sometimes while underway, the lights will turn off or flicker, but the bike stays running fine.

This issue started happening a couple months ago or so. After searching forums (including this one) the fix was to clean the starter commutator and inspect the brushes. I took a can of Lectra-Clean to the starter and cleaned the commutator with emery cloth (is that the right stuff to use?). With a shiny commutator and decent brushes (did not replace) I put it back together and starting was fine.

...until this week. It started acting up again so I decided I'd order brushes, which are due in Friday. It was so bad this morning that I couldn't get the bike started despite rocking it for a while. While rocking I could get the lights to flicker a tiny bit but couldn't get it in a good "spot" for the starter to want to engage.

Am I on the right track with cleaning the commutator again and replacing the brushes? Is there anything else that could cause this? Main ground cable and starter cable are clean (cleaned them when I serviced the starter).

Can a weak battery make this worse? It seems like my AGM battery has been spinning it a bit slower in the morning but it has been below 40f lately.

Thanks guys

[Inge K.]

About changing the brushes...it sounds to me that you're on the right track.
About a weak battery.....when the voltage goes down the ampères goes up to carry out the same
amount of work.
So yes it puts more load on the starter circuit and you're also in the risk zone to fry your starter relay.
It could be a good idea to have your battery load tested.

[kioolt]

Your're on the right track with the starter.  It's possible that the brush leads maybe catching on the brush holder if you weren't careful when you cleaned the starter.  Also it's not a bad idea to check the brush springs also for good tension.

[F14CRAZY]

thanks for the input. It sounds like I'm doing the right thing though I'm afraid that when I open it up later today I'm going to find that the brushes are used up. I was thinking that perhaps the roughness added to the surface of the commutator from the emery cloth I used may have caused what was left of the brushes to go to hell more quickly. This time around I'll finish it off with something smoother like 800 grit sandpaper.

I'll charge the battery tonight and see about bringing it to a parts store and having it load tested.

In the meantime I may be bike-less until the brushes come in on Friday. I theoretically figure that I could fool the load shed relay to keep the lights on and start the bike by popping the clutch but I don't like on a hill and getting the bike to move at any speed by myself is difficult enough.

[pdg]

If by 'emery cloth' you mean the stuff that's around 60grit or less, that'll leave the comm. far too rough. IMO, the commutator surface should be as close to a mirror shine as you can achieve without using any sort of polish.

The last time I cleaned up a comm. (on a generator but the principle is the same) I finished it by using 1200grit wet/dry paper, and I used it wet. Well, damp really, I just kept rinsing it off... To complete the job, I put the brushes in and using a strip of 1200 around the comm. I profiled the brush faces (they were a bit scored before I started). The larger you can make the contact area the better the current handling will be (i.e. the brushes should be profiled o the comm., definitely not square). This treatment on a motor will mean it should draw less current under load too.

[F14CRAZY]

I think it was 120 grit... the stuff that comes in a roll. Used tons of the stuff as a plumber in prepping copper pipe for sweating.

At any rate it sounds like I left it a bit too rough...the forum posts I came across didn't say anything about doing something like polishing the surface, though if brushes are as soft as they seem to be that would make sense.

I guess I'm hoping there will be something left of my brushes when I open it up tonight

[Inge K.]

If the commutator isn't to worn or scored, it's enough to use a pencil ereaser to clean it.

[F14CRAZY]

...I probably scored it with my 120 grit sandpaper

[rbm]

Inge's right --  a pencil eraser is plenty abrasive enough to remove corrosion.  When I first started working, my first job involved reconditioning electronic equipment.  We used pen erasers to clean switch and relay contacts.  If abrasive paper is used, 600 grit is plenty abrasive; 120 is way too rough. 

[F14CRAZY]

I picked up some 800 grit from Home Depot and wet sanded the commutator with just a tiny bit of water. One brush looked good but the other was kind of bottomed out as the wire going to it was getting caught in its holder (if that makes sense). Almost got it to start ONCE then was back at square one. Guess I'll be waiting for the brushes