One more happy /5 owner

[The_tober]

Hi there,
I just got myself a 71 R75/5 a couple of days ago and I am really excited!
I'll post some pics later but here's what I (think) I got:
- Built in late 1970, so technically a '71.
- I'm 4th owner. The guy I bought it from had it for about a year, replaced a few things but did not ride it much. He actually did not even register it.
- 23KM
- Good overall shape
- Original seat
- Original pipes
- Bing carbs
- newer tires
I paid $3500 which seems fair.

This is not only my first BMW, it's also my first classic bike. I was on recent Japanese bikes prior to this.

I'm on day 3 and I think I figured out the right starting procedure for the bike. The electric starter does not work so I have to kick start it. After many frustrating tries yesterday, i found out that opening up the throttle a bit gets it going with 3 or 4 kicks. Then I need to babysit the RPM a bit until it gets nice and warm.
I tried to use the choke, but it does not stay open in place. Any idea how to fix that? Is is a problem with the cable?

I guess one of the first order of maintenance is lube. The clutch and brakes are pretty hard to pull on. The throttle is also quite sticky. It will come back slowly though (and yes I checked the "cruse control"). So, first newby question is: Should I lube the cables? If yes, any recommendation on what to use? What's the correct procedure?

I have a couple of electrical problems which I will tackle as well.
- First is the starter as I mentioned. When I push the switch it just goes on a clack-clack-clack sound at a fairly high speed but does not turn the engine. Not sure what's going on there.
- Second is the horn. For this I suspect it's only the switch but this seems odd. I checked and I do get 12v to the horn when the ignition is on. Activating the switch is supposed to ground the other side but it remains floating. Since the horn button is combo with the headlamp controls it's pretty crowded in there but I was able to check that I get a good ground at the switch itself. Any history of these giving out?

I did have an issue with the left side signals not blinking. Since the right side was blinking fine, I figured the relay was OK. I looked at the bulbs (both of them did lit) and the front one was a 12W when all the others where 21W. I replaced it to a 21W and sure enough, we're blinking on all sides .

Once I get the manual I'll have to get in there and check the valves. I think I do hear a bit of a click in there and I want to make sure everything looks good.

BTW, is 98 Octane a good choice for this bike?

[anderson7585]

Congratulations,
I am constantly being surprised at how easy the /5 is to live with.

I have the same, exact "horn issue" as you but I have not had a chance to dig into it yet.

I have a "little" turn signal issue, when signaling for a right-turn the signals are on-steady at idle but as soon as I throttle-up a bit everything works as it should.

I ordered Albert-style headlight mirrors and a headlight "crash guard" from Vech today and the $ is leaving tomorrow for a parts-manual from Hucky's.

Vince

[The_tober]

OK, here are some pics. This is how I got the bike.

[schrader7032]

Congratulations on your new ride. Many smiles and miles!!

Cables: the cables should be teflon lined and any lubrication will help temporarily but will eventually just attract dirt. Try some light oil...they actually make a cable lube...check a bicycle shop. But the real solution is new cables. You should also inspect and lube the throttle mechanism at the hand grip. This could be the source of some of the drag.

Starter: you should really get this fixed. The kick start should be used for emergencies as the internal mechanism is not as robust as it was during the /2 days. The problems could be simple. Battery - is it fully charged. Also be sure you have a good ground (don't tighten the transmission ground bolt too much!) and that the battery cables aren't internally corroded. Starter relay under the tank - the contacts could be corroded, not allowing all the contact to latch to send full power to the starter. Find the relay and pull it out and replug it several times to clean some of the corrosion off the prongs. Or buy a new one...they're really not that expensive. There are aftermarket ones that could work, but they might not have the correct pin-out or internal wiring. Connections at the starter - you could have corrosion build up on the connections. Starter itself - if those don't help, then you'll likely need to pull the starter for testing and/or rebuild. There are some websites available that can walk you through a rebuild.

Horn: take the horn off and use separate wires to hook the terminals up to a battery. If the horn works fine that way, then you have wiring problems. If the horn still doesn't work, you might need to look at the back side and see if there are some adjustments. Typically there's a small screw which adjusts the points gap inside the horn. If there is, then experiment with the screw to see if it makes any difference.

Valves: Ticking valves mean happy valves. If you hear no sound, then you have a problem.

Gas: 98 octane? You must be downunder or at least not in the US. That sounds like the hi-test stuff. Your bike shouldn't really need it. It only needs the highest octane to keep it from pinging or pinking. Get the bike in tip-top shape tune up wise and then consider lowering the octane level until you find what she wants.

You should acquiant yourself with Mr. Fleischer aka Snowbum. He has a massive amount of info on-line...if you can get through his penchant for changing font and colors!

http://bmwmotorcycletech.info/techindex.htm

Another good source is Duane Ausherman's website as well as Anton Largiader:

http://w6rec.com/duane/bmw/index.htm
http://www.largiader.com/

There is another website specifically geared for /5 owners. I'm unsure about the "health" of this site...everytime I try and go there, my anti-virus programs kick up a fuss. Probably OK, though...at least it has been in the past:

http://www.5united.net/

[R.D.Green]

Very nice looking bike and a nice price. Congrats! The "built in" reflectors on the sides of the turn signal housings were only on the early /5's. They haven't been available for a long time so take care of them for originality's sake. Yes, get the starter fixed for sure. The "clack-clack" sound may indicate a weak battery but check all the other stuff as well. Also check your generator brushes and make sure you're charging. In the meantime, don't kickstart it on the sidestand. The original /5 sidestands are not very stout and you could easily bend it or worse. I don't think the original cables on the /5's were teflon lined so lubing is a must. Maybe time for them to go anyway. Vech sells cables that are now teflon lined. Yes, check the valves. A cup of coffee, some oldies on the radio, no more than an hour's time and you're done.

[The_tober]

Vince, funny you have the same issues with horn and blinkers. For the blinkers, I had one side that would come on but not blink. I checked the bulbs and on that one side the front bulb was a 12W when all 3 others where 21W. I figured the originals were 21W so replaced the front one and it worked right away!

Kurt, here's what I did with the horn:
- Disconnected the 2 wires to the horn and hot wired it to a weak battery. It honked so I knew it worked.
- With the ignition on, I checked that the green wires got me 12V to the horn. Fine.
- Activating the switch closes the circuit to the ground. I checked and even when pushing the switch, that wire is floating.
- I left the original hot wire connected to the horn and re-wired a $2 push switch for the ground. Works like a charm. I zip-tied it to the handle bar and off we go.

Not pretty but good enough to go to the DMV and get the bike registered. I guess I will order a switch.

Thanks for the tip on the starter. I have to admit though, I find it quite rewarding to kick start it, in a manly sort of way. So I'll start debugging that. I guess I need to get a good feel for the battery and charging system anyway so I will start there.

I also found out today that the clutch slips. I had not noticed because I did only highway when I rode it home. Today I did city traffic and when the bike got hot the clutch started acting up. I find it odd with 23K miles. could it be because it's just old anyway? Or maybe needs adjustment? How hard is it to replace on this bike?

Next I'll need some rear shocks (later). It also feels like the rear brake is here for aesthetic purpose only. I'll need to get on that soon.

[schrader7032]

Definitely do a proper clutch adjustment first. If that doesn't fix it, then you may have oil on the clutch or the clutch could just be worn out. Here's Tom Cutter's procedure for adjusting the clutch/cable...works great:

"Do a complete, "from scratch" cable adjustment after replacement. To do this:


1) Replace cable, both ends now disconnected.

2) Loosen locknut at transmission lever, slacken adjuster screw several
turns out.
3) Insert top end of cable through adjuster, into the lever slot, pushing it
WAY in to the lever. Slip the greased barrel up onto the cable, and pull the
cable back to engage the barrel on the cable. Clean and examine all parts to
see that the barrel only goes in one way.

4) If the cable is routed properly, and the top barrel seated correctly, you
should be able to hook the barrel on the lower end into the forked clutch
arm at the transmission.

5) The first adjustment is made with the large threaded adjuster at the top,
lever end of the cable. You need to measure the cable dimension at the LOWER
end, and make the adjustment at the TOP end. The dimension should be EXACTLY
201 mm from the rear face of the transmission where the cable comes through,
to the near edge of the cable barrel. You may need to turn the top adjuster
out quite a ways to obtain that dimension. Squeeze the clutch lever and
remeasure, as that will seat everything.
The easy way to measure the 201 mm is to cut a piece of coathanger to the exact length and use it as a guage. Put a piece of duct tape on the middle like a flag, write "BMW Clutch Adjustment 201mm" and you got a free BMW Special Tool.

6) The second adjustment is made at the rear of the transmission, using the
adjuster screw and locknut on the clutch arm. Turn the adjuster bolt in until
there is NO free play on the cable, determined by lightly pulling the lever
with one finger and looking at the gap at the hand lever where the cable
passes through. Once you have removed all free play, back out the adjuster just
enough to give 2-4 mm freeplay at the hand lever. To hold the adjustment while
securing the locknut, just pull and hold the clutch in with your left hand
while snugging the locknut with your right hand.

Test ride the bike, and recheck the two dimensions after the bike cools off.
You will note that the freeplay will change slightly when the bike heats up.
Don't readjust when hot. If you have the cold play adjusted correctly, there
will be adequate freeplay to accommodate the change when hot."

Probably in the next month or so, I'll be changing the clutch on my /7. It's a straight forward procedure. Here are the basic steps:

Remove carbs
Drain driveshaft fluid and trans fluid
Disconnect battery at trans breather bolt
Disconnect neutral switch wiring
Remove Battery and tray
Remove airbox
Remove clutch cable and arm
Remove forward drive shaft boot clamp
Remove driveshat-to-trans bolts
Remove left foot peg and shifter linkage (and arm)
Support Trans with blocks of wood
Support swingarm with blocks of wood or staps
Remove rear wheel
Remove swingarm lock nuts, then pivot pins and slide swing arm back
Remove trans-to-engine bolts/nuts
Slide trans back and to the left

At that point, you'll be looking at the clutch pack. The pack is held in with some spring tension, so you'll have to remove 3 of the 6 bolts first. Then replace them with longer bolts with nuts and washers...I think 75mm is good...I forget the pitch of the threads. You then thread them back into the three open holes and run the nuts/washers down to the clutch. Then remove the last three clutch bolts. Finally, evenly backing off the nuts/washers will control the release of the spring tension in the clutch.

[olderbeemer]

Vince

Glad to hear you like the bike.

Not sure the about the issue with the turn signal. However, as far as the horn, I think if you start looking with the switch, you may find the connection to ground is the issue. I think this happened to me once also. As I recall, I removed the switch, and it seems like the screws that hold it in place are also the path to ground to complete the circuit. Seems like it didn't make good contact. I reinstalled it and it worked. The horn itself should be fine.

Roger