Bmw R65 1981 Starter problems

[NorR65]

My R65 has a starter problem when specially when engine is cold.
I hear a "click" and the starter engine spins a few revolutions.
When I try again after a few seconds nothing, no click.
If the engine starts I get the following readings with my multimeter:
I measured at the positive and negative poles on battery.
Before starting 12,70 Volt. When pushing starter button 7,5V which raises to 10.5V after a few seconds. When stopping starting procedure Volt is raising from 10,5V to 12V takes at least 30 seconds.
When engine at 3500 rpm 13,4 Volt.
Starter is Bosch and the R65 has at least 83.000 km.
I have dismantled the starter, could not see anything wrong, cleaned it and put it back on bike. Still has a starter problem.
Any ideas? Bad starter? Bad negative from battery or starter?

[Red_Hen]

Could it be the starter relay is on the blink or a corroded wire?

[tvrla]

Could be either the battery or the starter. But I suspect the starter at this point.

What goes bad in these starters is the bushings. There are either two or three bushings to replace (don't recall exactly how many), and when they go bad, the starter doesn't work very well. It draws a lot of current and acts very sluggish. Also, if you're not even getting a click out of the starter, that tells me the solenoid needs cleaning up as well - the contacts get corroded and don't conduct any more.

[Bob_Roller]

There is a 'sintered' bushing at each end of the armature shaft .

A sintered bearing is a powder or granulated metal that is pressed into the bushing shape .

Another name for this bushing/bearing, is an oilite bearing .

To lubricate them, you 'soak' them in oil, the oil gets trapped in the spaces between the powder/ granulated metal and seeps out over time and lubricates the surface between the bushing/bearing and the shaft .

With these bikes going on 30 years old, it's a good bet that there isn't any oil left  in these bearings .

The pivot points on the assembly that's moves the starter gear also needs to be lubricated with a high drip point grease, one that has a high melting point, it also has to be a non-conductive grease, so it doesn't cause any electrical issues if it gets thrown out in the area of the brushes .

The solenoid has a movable core, it has a large copper washer that completes the circuit inside the starter to provide a path for the power to get to the brushes .

Not uncommon to have 200+ amps across this contact area during starting, the mating surfaces get pitted and sometimes develop high spots that limit the amount of contact area and reducing the current flow to the brushes/armature .

These areas need to be filed smooth again, or replaced if they are in really bad shape, when disassembled and inspected .

Also, how old is you battery ?

Motorcycle batteries aren't the most robust batteries and don't like to be run low on electrolyte, if it is a serviceable type battery .

[NorR65]

Thanks for your ideas.
Battery is a 2 years old Exide sealed battery.
The cheapest and easiest solution is to buy a new Valeo D6RA15 on Ebay. But it is no point to use money before I know what the problem is. The whole idea owning an old BMW is to try to repair everything myself.

[Bob_Roller]

Do you have a starter/generator/alternator repair shop in your area ?

These starters were quite common in the early '80's .

I know locally, it's about $50US to get one refurbished, if no parts are needed, just a good cleaning and lubrication and possibly having to replace the bushings/bearings at the ends of the armature shaft isn't much more cost .

Also, when you have the starter removed from the bike, clean up the contact area between the starter and engine case as well as the hardware that holds the starter on .

The return path/ground or earthing point for the starter is through this contact area .

Here's a couple of links to give you an idea what it takes to disassemble the starter, clean and lubricate it  .


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


http://gallery.oldholden.com/Jack_s/Bosch+Starter+Motor/

[NorR65]

I have a starter repair shop nearby. But I am afraid it will be more expensive to overhaul than buy a new from Germany or Great Britain.
I wonder way I do not hear a "click" from the starter relay the second time I hit the starter button? Has voltage drooped to low after my first attempt to start?

[Bob_Roller]

It sounds like the battery isn't fully charged .

If you have a battery charger, leave it on overnight and try it again the next day and see if it makes any difference .

With a good starter and battery, the battery voltage should not drop below around 10.5 volts and this is with the starter rotating .

Have you kept the battery on a float type charger during the cold season when the bike is parked for the winter ?

[NorR65]

I did use a battery charger a few times during the winter months.
Maybe not often enough.
The bike with battery is parked in a garage with temperatures between -5 and +5 degrees Celsius in the winter months.
When I charged the battery yesterday my multimeter showed 12,74 volts. Is it not fully charged then?

[Bob_Roller]

How long was it left on charge ?

If you're not using a motorcycle battery charger, it may over charge the battery if left on overnight .

A fully charged battery should be around 13.5 volts, before putting any load on it .

[NorR65]

I have a CTEK charger which turns off when maximum voltage, 14.7 V is reached. I charged the battery approximately 15 hours.

[Bob_Roller]

I think your battery may not be in good 'health' .

Don't know if you are able to do this or not, but if you can connect jumper cables from an auto battery to your battery cables on your R65, with the bikes battery removed,  see if your starter issue is gone, or at least better .

You don't need the vehicle that you are using, to have the engine running, just the battery itself will be sufficient .

[NorR65]

Thanks Bob
You got me thinking. I have another MC battery which do not fit in the R65. It has been stored in a warmer room during winter. I will charge it to night and try starting tomorrow morning, in about 12 hours.

[Bob_Roller]

Actually, if you keep your battery in a cold environment, the battery lasts longer, as long as it isn't allowed to get discharged, then there's the possibility of the electrolyte freezing and causing internal damage to the plates, or cracking the case of the battery .

Heat is not a friend of a storage battery, in my desert climate, my average motorcycle battery life is around 2-3 years .

The average temperature in the garage from mid May to the end of October is around the mid to upper 90's F. (35-37 C.), temps in the 105F. (41 C.) area in the garage are common in September when the sun angle is getting lower and the garage door is exposed to more of the direct sun .

I'm new to battery 'tenders', but in the 2 years or so that I have been using them, I would now recommend them anyone that has a motorcycle, or 4 wheeler that gets limited usage .

When the bike is parked for the day, the battery tender is connected to the battery, until I use it again .

[Barry]

When I charged the battery yesterday my multimeter showed 12,74 volts. Is it not fully charged then?  

Measuring the battery voltage just after it's come off charge can be misleading and would normally produce a higher figure than 12.74 due to the surface charge effect. To get an accurate reading the surface charge needs to dissipate which will cause the voltage to drop slowly over a period of 6 hours or so. If you still get 12.6 volts or above after this resting period that would be one indicator (but not a guarantee) that the battery is good. If you read 12.74 volts straight after charging then the battery is either not fully charged or it's faulty.

To determine if a battery has reached full charge a good rule of thumb is to measure the voltage while it's charging. When it rises to 14.4 volts it's about there.