Barn find starting troubles

[pruttel]

Hi All,

I finally found time (and space) to work on the 1979 R65 my dad found in a chicken shed. I first reported on this find here:
http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1280225088

So over the summer I have been fixing up things. Here's an incomplete list:
* The crank didn't turn. At first I thought that pistons could have seized or something else rusted shut, since it had been standing in this open barn for some 5-odd years. When checking the oil level it turned out that the engine had been topped off completely with fresh (clean) oil, so after draining and refilling with the proper amount it allowed itself to be cranked again. Yay!
I inspected the chambers through the spark plug hole, they looked dry except for the cylinder wall.
* The carburetors were completely gummed up. Complete rebuild of both; new gaskets, rubbers etc. plus an ultrasonic cleaning of the body and parts.
* The front brake (single disk ATE) was seized on both ends. Pulled everything apart, cleaned and partly rebuild, polished the caliper pistons, put everything together, turns out that the longest brake hose was plugged with rust. I'm awaiting a second hand one from eGay right now. In the meantime found out that the master cylinder was still leaking so I'm bidding on a 2nd hand one as well.
* The keys were gone, the filler cap was rusted shut to the tank. I drilled a hole in the filler cap to fix the two parts with a screw and I unscrewed it with lever. It was completely rusted, see photos below. I dismantled the cap, ordered some key blanks and started to file a new key. Once I managed to do that, I also opened up the contact key lock, cleaned everything and filed a key for that one as well. (Different key codes *of course* Pfffff...) Now both locks run smooth as a baby's buttock again! Also got new rubbers for the fuel cap.

So last weekend I tried to start her with help from a colleague who rides BMW for over 30 years now, but we couldn't get further than a click click click click clack clack of the starter motor. So after a few clicks, the sound changes to a different clack.

Now I don't really know what would be the logical next step to check…
Do I need to check/clean/re-grease the starter first, as mentioned by nhmaf in this thread?  
http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1314909923

Or is an inspection of the contact points in order?

Where to start?

Iwan

[montmil]

Battery and positive/negative cable condition. Terminals may be corroded. Battery may be flat. Consider purchasing a Battery Tender Jr and keep it plugged in. If it then turns over, check points gap and do a static timing check.

Still, no joy then spend some time checking all wiring terminals within the starting and ignition system.

After getting the battery up and going with the engine cranking, remove the sparkle plugs, ground them securely to the cylinders and see if you get a spark from the plugs.

Fuel, air, compression, spark... vavoom!  Might not be pretty be that's where you'll begin.

Monte

[Bob_Roller]

First, how old and what condition is your battery ?

If it's a new or known good battery the starter I would look at the battery cables at the ends, they can get corrosion under the insulation and cause problems.

If these check out alright, I would suggest removing the starter from the bike, place it in a vise and connect battery jumper cables to it and see what it does then .

The starter may need to be disassembled cleaned and lubed, not too uncommon with a 30 some year old vehicle .

[pruttel]

Oh I completely forgot to mention: this was with a fully charged car battery from a Volvo 740, connected through starter cables. The bike battery was missing, I have a new one ready to fill up and mount but I wanted to wait until I got it running so I tried to start with an 'external' battery.

What I also forgot to mention is the fixed earth connection from the front coil, this one was hanging loose. The brown wire is now screwed to the metal parts where the connectors are fixed in. (as in that other recent thread)

The starter is pulling a lot of current, I can tell from the lights getting dimmer on starting. It does seem to turn, but I don't know for sure. Easiest way to check that would be to look at the rotor in the front while starting?

[Bob_Roller]

Can you turn the engine over using an allen wrench in the bolt that holds the alternator rotor on ?

You may want to remove the cover on the top of the engine and check the electrical connections at the starter, may be corrosion there as well .

I've gotten a bit far from corrosion issues on these bikes, having lived in a desert for the last 18 years, I just don't get any real life experience anymore, I have barely gotten 1 inch (2.54cm) of precipitation since January first this year .

[Barry]

Sounds like we have a Lock Smith in our midst....impressive work !

My money is on the starter grease being dried out.

[pruttel]

Can you turn the engine over using an allen wrench in the bolt that holds the alternator rotor on ?

You may want to remove the cover on the top of the engine and check the electrical connections at the starter, may be corrosion there as well .

Yes, it can be turned over, either by allen wrench or by the rear wheel.

I've gotten a bit far from corrosion issues on these bikes, having lived in a desert for the last 18 years, I just don't get any real life experience anymore, I have barely gotten 1 inch (2.54cm) of precipitation since January first this year .

Over here This year has been the wettest in my lifetime! (Almost 40 years worth)
It feels like we haven't had any summer at all, spring just went into autumn  :-/
 

Sounds like we have a Lock Smith in our midst....impressive work !

My money is on the starter grease being dried out.

To be honest this is the first time I've disassembled a lock. It's not too difficult to make a key once you figure out how it works. I could have made better (read: less blurry) pictures though.

I'll check all the things mentioned above.

[Barry]

To be honest this is the first time I've disassembled a lock. It's not too difficult to make a key once you figure out how it works.

Once you have them in bits it's easy to see how they work. I did a similar job when the ignition lock got worn on my 22 year old Merc.

I dismantled the lock and  removed all the pins then re-ordered them leaving out the shortest worn pin. I think there were 13 pins so I only have a 12 pin lock now. I was just happy it worked.

[pruttel]

Ok, checked the sparks: sparking fine.

So I removed the starter motor and tried to fire her up. The axle does come out, but it doesn't rotate. I assume that's the lockup by dried grease?

[Barry]

I assume that's the lockup by dried grease?  

... or maybe worse like the starter is faulty or seized up in some way.

Is it the original Bosch starter or could it have been replaced with a Valeo starter ?

Either way a strip down is in order.  I just asked because the early Valeo starters fitted on some of the later BMW's had a tendency for the permanent magnets to come unstuck from the case and jamb the starter.

[pruttel]

It's the original Bosch, I got it on the bench right now. Gonna open it up tomorrow.

Also, I just scored a 2nd hand starter on eGay. Located in Germany though so I'm gonna pick it up somewhere next week when I'm in the neighborhood. Scored some brake parts too, yay!

[pruttel]

Ok update. Haven't had a lot of time to tinker between then and now, but last weekend I finally got around to do some.

* I have a nice looking white/blue spark on both sides.
* The starter rotates, but not fully. I can see the alternator rotate for half a rotation until it cannot get through the compression, then it clicks a lot and slowly goes through it. If I remove the spark plugs and ground them properly on the fins, the starter can get the crank to rotate without problems, and I get the sparks noted above.
Does this mean that the starter can't get enough current to fully pull it through? The starter is a Bosch.

And then this: I found a loose connector under the tank, close to the rear coil. The black one coming from the top right connector, see pic:

Is this supposed to be loose? None of the non-connected spades on the coils look as if it has been used before, and I cannot find a spade that looks like it has been the home of this connector... Weird!

[pruttel]

To answer my own question about the loose connector: I think it is supposed to be loose and it is connected to the starter relay. See this handy schematic that I found on the german 2-ventiler website: http://dl.dropbox.com/u/17081629/r65/SchaltplanR45R65ab78.pdf

I think it's the -0.75 SW- connected to (34) which is the starter relay (good thing that ich spreche ein bisschen deutsch

Iwan

[Bob_Roller]

There is a single black wire connected to one of the coils, it is the electrical signal for the tachometer .

[Barry]

I looked at a few other wiring diagrams and if that loose black wire does come from the starter relay then it is used on US models only where it connects to the headlight relay to turn the light off when the engine cranks.

To confirm this it should go live when the starter is operated.