Author Topic: BMW R100 Airhead (Read 34644 times)

Scott S · « **Reply #75 on:** February 23, 2016, 01:32:54 PM »

I caught HELL today trying to get the rear wheel off by myself. I had to enlist the help of my Dad and remove the rear disc to get it off. I think that the old tires were at least part of the problem. Even after deflating the rear, it's so old and hard that it held it's shape!
I finally got it off, though. Took the opportunity to lift the rear caliper and bleed it some more. I did get a little more air out. I also degreased the wheels. The rear in particular was pretty grungy. This is about the best I can do with a few can of degreaser, some Simple Green solution, and assorted brushes, SkotchBrite pads and elbow grease. It'll do for a garage build. I'll let them dry and air out for a few days, wipe them down with some acetone and use some wheel paint on them.
I also cleaned up the rotors. I'll deglaze them and clean with brake cleaner before installation. And the rear splines will get some high pressure moly lube, too.

Terry in Australia · « **Reply #76 on:** February 23, 2016, 03:07:35 PM »

Are you gonna dump those crappy old tires too mate? I'd hate for all your good work to be wasted if your tires fall apart the first time you ride it? As I keep saying, the cheapest new tire is safer than the most expensive old tire.....

Scott S · « **Reply #77 on:** February 23, 2016, 04:06:23 PM »

Oh, heck yeah. The bike came with two brand new Michelin Pilot Activ tires.

I'm looking at brake pads too, while I'm in there. I like EBC and I believe I'd prefer the organics since they don't squeal and wear the rotors as fast. Is the EBC FA18 what I want? Are they the same front and rear for the triple Brembos?

Terry in Australia · « **Reply #78 on:** February 23, 2016, 05:43:07 PM »

That's a good question mate, I replaced the pads on my R100RS 3 or 4 years ago so I don't remember, but I think you're right that the pads are the same. Moto Bins in the UK are an excellent source for parts. Cheers, Terry.

ofreen · « **Reply #79 on:** February 24, 2016, 05:20:25 AM »

I may have missed it but have you done a spline lube? If you haven't, I strongly suggest you get in there and take a look.

Scott S · « **Reply #80 on:** February 24, 2016, 05:50:52 AM »

On the gear box? No, not yet. I will be lubing the splines on the final drive/rear wheel.
The gear box was off sometime before I got it. I actually talked to one of the previous owners from about 4 years ago and a shop that serviced it.
It's been in the 3 or so years in between then and me that it's been....neglected.

ofreen · « **Reply #81 on:** February 24, 2016, 09:14:34 AM »

Quote from: Scott S on February 24, 2016, 05:50:52 AM

On the gear box? No, not yet.

Yes, the splines on the transmission input shaft. The splines are dry (if seals aren't leaking), and are fine cut. They can rust and crumble away until one day you go to leave from a stop and just sit there. You have to slide the transmission back from the engine a bit, with some disassembly required to get to that point. There are plenty of instructions on the interwebs including the airhead site. Snobum's write up is thorough, as usual. Not too bad of a job, especially after you've done it a few times. I would do it before you ride it too much. Now would be a good time if you still have the rear wheel off.

Scott S · « **Reply #82 on:** February 26, 2016, 05:45:28 PM »

Now that I have the S fairing off for paint, I can get good access to the clock and voltmeter wiring and lights.
I was pleasantly surprised to find the clock works.
However, the lights for both gauges are always on, even when the key is off. I can see constant power to the clock, but the backing light, too?
If I ground either bulb to the frame, they light up. The lights shouldn't be always on, should they?

To clarify: At rest, there is no voltage to the volunteer. It works when the bike is running. Even with the key off, if I plug in the meter and insert the bulb the light comes on.
There is always voltage to the clock, even with key off. If I plug it in, it works and the light is always on, even when the bike isn't running.

I see on the diagram that they share a brown wire with the front turn signals and brown appears to be ground.. The signals are also off the bike right now (to remove fairing). Would that have an effect on the circuit?
And as I said I understand keeping voltage to the clock, but why are the lights in both gauges constantly on right now?
(Forgive me; electrical is a weak point of mine)

RAFster122s · « **Reply #83 on:** February 26, 2016, 10:23:21 PM »

You are going to keep going and fix all the PO's gremlins leaving none for the next guy...calj...
You know his love of arp fasteners, you really need to slow him down a few times to make him feel like he got a good deal.

So, where are you going to stop and move your deductive skills to a more satisfying target.

calj737 · « **Reply #84 on:** February 27, 2016, 02:43:55 AM »

Scott - post the wiring diagram you're using please.

David - ARP fasteners are the BOMB and I'd have thrown the stock harness out and used an M-unit from MotoGadget and been done with these electrical gremlins

Scott S · « **Reply #85 on:** February 27, 2016, 03:48:52 AM »

I have a Haynes manual and looked over the diagram in it last night.
Looks like I'll be going over the wiring and fuse panel in the headlight bucket soon....

Scott S · « **Reply #86 on:** February 27, 2016, 03:53:22 AM »

And the clock and voltmeter lights work as soon as they're grounded, either to the frame or to the gauge housing.

When I turn on the key the headlight comes on, as well as the idiot light cluster (neutral, oil, etc ) but not the tach and speedo lights.
I'm unable to crank the bike at the moment. Would the tach and speedo come on once it starts charging? Or do I need to trace those out, too?

Roach Carver · « **Reply #87 on:** February 27, 2016, 06:24:21 PM »

Quote from: calj737 on February 27, 2016, 02:43:55 AM

David - ARP fasteners are the BOMB and I'd have thrown the stock harness out and used an M-unit from MotoGadget and been done with these electrical gremlins

I would like to hear a little about the m-unit. I bought an old Ducati and the factory wiring hurts my head. Sorry for the thread jack.

calj737 · « **Reply #88 on:** February 27, 2016, 07:29:16 PM »

There's a thread open asking for "input" about it with Pro's and some "nay-sayers". Check it out. IF you have further ?s, PM me. Sorry, Scott. Did you sort out the power issue yet?

Scott S · « **Reply #89 on:** February 28, 2016, 04:12:51 AM »

No, been working all weekend. I'll get around to it soon. Luckily, it seems like I just have to trace out and move around some wires.
I'll probably wait until I get the wheels back on it. I'd hate to knock it off the stands.

Scott S · « **Reply #90 on:** February 28, 2016, 04:50:42 PM »

I'm trying to trace it out and, yes, it's a snakes nest in there. The bike is an '84 R100RS that someone has semi-converted to S spec. The wires for the clock and voltmeter backlights are connected where they should be on the board.
There are a few other issues, though. For example, the brake light works, but not the tail light. And I see some wires coming from the LH control that don't match any colors on the two diagrams I have. AND...there seems to be another grey/black wire with a bulb receptacle inside the headlight, just wrapped up in electrical tape (city light, maybe?).

It sorta seems that ALL of these issues are related....they all seem to stem from the LH control and/or light switch.....but I'm having a heck of a time sorting it out. There seems to be a common grey/black stripe wire that relates to lighting, but I'm having a tough time making sense of it all right now.

Scott S · « **Reply #91 on:** February 28, 2016, 05:27:24 PM »

New Info: The grey/black stripe wire that goes to the clock/voltmeter/tail light is HOT when the key is OFF and the lights go OUT when the key is ON. Hmmm....maybe pointing towards the key switch? That still wouldn't explain the tach/speedo backlighting, though.

Here are some pics:

This is the key switch

This is the grey/black stripe wire inside the headlight housing that seems to have a light socket on the end. It goes to a 6 pin connector behind the headlight bucket and then to the main harness....city light, maybe?

Mystery black wire coming from main harness

And this is a green/orange stripe wire that is coming from the LH switch. I'm 99% sure that it IS an orange stripe and not some faded color of red or yellow. I don't see anything that matches that on the diagrams.

RAFster122s · « **Reply #92 on:** February 28, 2016, 07:56:17 PM »

I am guessing that somewhere in the branch of the wiring for the voltmeter and clock there is a misconnected wire causing the back lights to remain on and powered up with the key off, then you end up powered when switch on or the switch changes things to deactivate the power. Could be a case of two wires causing the issue... The only way to find it is disconnect & test to see where it is getting the power or trace every wire in the harness. With the mods and a couple of bad POs I would do the later. Having some help to map it out and keep you on track is easiest with another person and a large board to map it. Then photo and draw it up smaller. Back side of a piece of plywood or break it down into various circuits for the systems (lights & signals, ignition, charging, etc.) Then you know what you have tofigure out where a misconnect might be. Were there relays that were pulled from the bike? Using existing lkght circuits to control relays with power for lights controlled by relays with heavier wire directly to components on headlight is a great mod. You could even put power for turns and running lights done this way to eliminate full load going through handlebar switches, but it would require some rewiring and you might not want the complexity or room for additional wires. Just isolating wires through switches to drive relays could be done to lessen/ eliminate wear on switches. But, what ain't broke...
I have seen and even caused a wiring problem in different part of my c70 when I connected a wire to the wrong wire when cleaning things.

Hate to ask but, naturally you checked the bulb and checked the brake light socket for any corrosion.
I have seen wires corrode when water built up inside the insulation. I know it is strange to think it can occur. I was surprised how it happened, because it was not close to any terminal on the harness. We are talking over 18 inches from the closest connector and in some cases more than two feet. Sometimes things are not as moisture resistant as you might think.
So, there is a slim chance the wire could have a break in it that is not apparent. A method I have used in extreme cases was a pin into the wire and a check for resistance at several points in the length unless end to end shows a break, you work backwards to find where good wire resumes then you cut into it to patch a good wire for the entire run, then dissect (?spelling? stupid nook browser) the original for a clue about its failure's cause.

Scott S · « **Reply #93 on:** February 29, 2016, 02:55:34 AM »

My buddy Pamco Pete has agreed to help me take a look at it. He's an electrical engineer and a friggin' genius.

The bike is an R100RS and someone has put an S fairing on it. The RS came with the clock and volt meter, and they appear to be plugged in to the correct color coded spot on the board in the back of the headlight.
There's a grey/black wire that is common to a lot of the lighting circuit and I'm seeing a problem with that wire at the front and back of the bike.

I'm having a heck of a time following the diagram because someone has done something different with the LH control....why, I don't know...and some of the affected circuit goes to the ignition switch and I'll have to remove it to get a better look at the markings on the back of it. There's also a relay involved and my understanding of electrical components is just too weak to figure it out.
Add in wiring marked with German abbreviations on the diagram and at least one factory colored wire that I can't find on the diagram and my eyeballs start to hurt.

I almost feel that when I find the problem, it will fix everything.

Scott S · « **Reply #94 on:** February 29, 2016, 04:04:12 AM »

Just checked the key switch postions, too. I used the voltmeter wiring to test for voltage, since it's easily accessible at the moment and should be hot when the key is on.

* OFF - Key is removable and no power to voltmeter, BUT.....the clock, voltmeter and tail light are all on. They all share a common grey/black wire
* Park - Key is removable, no power anywhere (didn't check tail light, as I have it unplugged right now to prevent battery drain)
* On - Power to starter, dash lights (oil, neutral, etc) and starter works. Bike runs in this position. BUT....gauge lights and taillight go out and speedo/tach backlights don't work.

Speedo and tach lights don't seem to be working in any position. I haven't checked the bulbs there yet. If I get the wiring sorted and they're still out, I'll check the bulbs.

Roach Carver · « **Reply #95 on:** February 29, 2016, 06:12:17 AM »

sounds like off and park are switched? I think I would start working through it one piece at a time. I would unplug the clock and the voltmeter ( I have mine in a storage tub). If you think the left switch is to blame I would isolate it and see what has been modified and spliced. I feel your pain. I really don't care for wiring.

RAFster122s · « **Reply #96 on:** February 29, 2016, 10:31:52 PM »

http://cx500forum.com/mediawiki/index.php?title=Color_of_Wires_and_where_they_go

The CX500, aka the Plastic Maggot for first two years (... one of which I own)
has this resource...

Maybe creating something like this would help you sort through it...
Was it Yahoo or Google that absorbed AltaVista's Babelfish app for translating pages and text from one language to another? It is handy but Chrome does it for me when I want...

Just for your use, doing it in a notebook can help you sort through things...very handy to have.
I once spent 3 days rewiring the engine bay of our '82 244DL after it smoked the harness after I screwed up and didn't reattach a connector block to its firewall holder. It rubbed the engine harness wiring against the intake manifold runner (aluminum) until it chafed through the wiring and then 12V to engine ground with exciting smoking results that scorched the harness in the engine bay across the firewall to the ignition box and even into inside the car up to the dash with one wire that melted into other wires.
A spool of Belden TNF (pre-tinned wire) good set of crimpers, quality insulated disconnects and wire marking tags, and loads of patience, tech help from friends across the country, and I dug through the car rewiring it by hand. The replacement harness was over $1k and I had enough vacation time and ability/drive to do it in below freezing temps in the driveway. And lots of hot chocolate as well as a good set of Carhart coveralls... Snowed part of the time as well.

So, you can do this if you just break it into bite size pieces to figure out where it is messed up. Might have a relay wired wrong feeding the instruments in key off while breaking connection in power on mode. Some relays have NO or NC options {(Normally Open circuit) or (Normally Closed circuit)}...where NO is off and NC is on for that circuit...

Scott S · « **Reply #97 on:** March 15, 2016, 11:00:56 AM »

A couple of hours, a couple of trips to the parts store and with the help of Pamco Pete (electrical engineer and all around genius), we figured it out today.

It appears that both the headlight and starter relays had been replaced. One of them was the wrong type. To make matters worse, the wiring diagram in my Haynes manual is wrong. It took Pete quite a bit of "ciphering" and making a jumper to prove the point, but we pinpointed the headlight relay as being wrong.

The diagram shows a 87 and a 87a contact, which is a SPDT relay but it should show two 87’s without the “a” suffix, which is a SPST relay. I think that is what messed up the PO because the relay for the lights was “correct” if the wiring diagram was correct showing the 87 and 87a contacts. That’s why we needed two trips to the parts store; the first relay that we tried because it matched the wiring diagram, but it was wrong.

All the lights now work as they should and in the correct key position. I determined that there is power to the tach/speedo. I think that they probably removed the bubs (just as they did with the clock, voltmeter and tail light). I bought new bulbs for them and the city light in the headlight. I'll get them installed and report back.
But.....I've run into a snag: Is this screw on the gauge housing broken off? I have the two lower screws out. Is there a third up top? I just need to get the back of the gauge cluster off so I can check and install new bulbs.

Scott S · « **Reply #98 on:** April 12, 2016, 10:42:09 AM »

Long time no update. Where to begin.....

After getting the wheels off and painted, I had the new Michelin Pilot tires mounted and balanced. I wrapped a little painters tape around a paint stirring stick and stuck them in the calipers while the wheels were off. When I pushed the pistons back in to get them over the rotors, I blew out the seals in the master cylinder. Doh!
Better now than on the road, I guess. I sent the master cylinder and a new BMW piston/O-ring kit to a buddy down in Alabama to be repaired. He reported that the bore was perfect but the seals were just old and rotten.
Then the master cylinder got lost in the mail.... :becca

It's since been found and is on the way. I have to get it back, installed and bled before I can continue with the bodywork. And speaking of bodywork.....

I had everything painted in Matte Graphite and Ho-Lee-Chit is it bad ass.

Scott S · « **Reply #99 on:** April 12, 2016, 10:52:51 AM »

However.... You didn't really expect all that to go without a hitch, did you? Not the way this bike has been...no sir...nuh-uh....

While the fairing was off and I had access to the clock, I was pleasantly surprised to find that the clock worked. Then I noticed that the bulb was flashing as I worked on the bike. Whenever it grounded on the frame, it was lighting up. There were a couple other anomolies, too. Like the missing bulb for the voltmeter, no back lights on the tach and speedo, an unplugged wire on the tail light....etc.
They all shared a common circuit and were all hot, all the time. Once again, I had to enlist the help of Pamco Pete to help sort it out. Long story short, someone had replaced the starter relay and the headlight relay. One of them was wrong. There was a circuit that should have been always open and they used a relay that was always closed. This caused much frustration on my part during trouble shooting. And, like SOOO many other things on this bike, rather than fix it properly, they just unplugged stuff.
A new $6.99 relay fixed it, but not until I spent HOURS chasing it.

Then, when the tank was at the bodyshop, they found a pin hole by one of the petcock bungs. The tank wasn't leaking before, but it also had several THICK layers of paint on it. I guess it's better they found it now.
It was soldered/welded up properly and the old, failing, factory liner was stripped out and the tank was lined with Redkote. It was tested for a couple of days at the body shop with paint thinner in it and it didn't leak. And that was BEFORE being lined.
I guess the upside to all this is that the ENTIRE fuel system has been cleaned now; from the tank, to the new petcocks, new fuel line, new inline filters and rebuilt carbs.

I also fabbed up a bumper for the center stand and replaced those god-awful yellow plug wires with some black ones. As soon as the master cylinder gets here I'll get some overall pics.

News:

Author Topic: BMW R100 Airhead (Read 34644 times)