Newbie with electrical upgrade question for 1972 75/5

[yourpalcal]

Hello, I recently purchased a 1972 75/5 and it in great shape except it needs a lot of electrical work. The starter was replaced and I have ordered new coils and wiring harness. This is my first motorcycle (I have only worked on dirt bikes through the years) so its a little daunting. My question is regarding on what ignition/electrical upgrades (if any) should I purchase for the bike? I live in Florida and plan to just ride the bike on the weekends around town. I don't plan to have any heated components or other items that would draw additional current. I want it to be as stock as possible but also minimize maintenance. While I am leaning towards a digital ignition upgrade of possibly Boyer or Endralast, would the alternator upgrade really be worth it for me? I am trying to figure out what’s really best for my situation within a modest budget. Thanks!

Calvin Rose
St Pete, FL
1972 BMW 75/5

 

[natepetersen85]

When I contacted EME they recommended doing the 280w alternator upgrade, just because of how weak the stock chargung system is. The shorter your rides the more you'll want the upgraded charging system. The /6 parts are better and pretty much drop right in.

I also did the electronic ignition upgrade that uses an optical sensor instead of the points, you just set it and forget it, and its been awesome so far!

Sent from my SM-G960U using Tapatalk

 

[RPGR90s]

Electrical

Hello, I recently purchased a 1972 75/5 and it in great shape except it needs a lot of electrical work. The starter was replaced and I have ordered new coils and wiring harness. This is my first motorcycle (I have only worked on dirt bikes through the years) so its a little daunting. My question is regarding on what ignition/electrical upgrades (if any) should I purchase for the bike? I live in Florida and plan to just ride the bike on the weekends around town. I don't plan to have any heated components or other items that would draw additional current. I want it to be as stock as possible but also minimize maintenance. While I am leaning towards a digital ignition upgrade of possibly Boyer or Endralast, would the alternator upgrade really be worth it for me? I am trying to figure out what’s really best for my situation within a modest budget. Thanks!

Calvin Rose
St Pete, FL
1972 BMW 75/5

I had a '73 R75 and it had a totally stock electrical system on it except I upgraded to a electronic voltage regulator. Never had a problem with anything. Even ran a heated vest in fall riding (southern MI).

I loved the stock points and condenser, which I almost never touched. Every few years I would swap it out for new, clean the advance weights, grease everything and it was good to go.

Lots of cases for changing out for higher output alternator's, electronic ignition but to me, the beauty of an old bike is that I get to work on the stock systems. If in good shape, the original Bosch electrical system is extremely reliable. you're changing out the harness which is very smart. IMHO, leave it original and enjoy it.

Rick

 

[20774]

Welcome to the forum, Calvin! I agree regarding the adjustable voltage regulator. Since it is your intention to putt around town, you won't get the full charge to replace what you loose during starting. You might also want to invest in a smart charger or tender so you can keep things topped up every once in a while. When you notice the starter start to drag upon start, then it's time to put the charger on it before the next ride.

 

[chunk]

Yep, have to agree, a well sorted charging system and a battery tender is all you'll need in my experience. Keep it stock and simple, not the most robust charging system around, but perfectly adequate for the task.

 

[Friedle]

Hello Calvin, If you haven't yet done so I would highly recommend joining the Airheads Beemer Club www.airheads.org They have a large and very active group in Florida with many activities and hands on Tech Days. The FL Airmarshal, Kevin Reimer, is a really helpful guy and very knowledgeable with all aspects of Airhead upkeep.

It's the perfect holiday gift for yourself.

Friedle
NY AM
ABC BoD

 

[yourpalcal]

Thank you for the feedback everyone! I did call EME per the suggestion and Norm was awesome. He said my idea for the new starter, coils, relay and harness should be enough since I am in Florida. He also suggest a battery tender (as suggested above) and possibly consider the electric ignition down the road. I appreciated the honesty.

Here is a pic of my bike. I could not be happier! I had planned to buy something that needed more work but the price was certainly fair. The guy who sold it to me did all the engine and cosmetic work to have it back to original. The electrical was all original and in bad shape but gives me a few projects.

View attachment 71914

 

[chunk]

Thank you for the feedback everyone! I did call EME per the suggestion and Norm was awesome. He said my idea for the new starter, coils, relay and harness should be enough since I am in Florida. He also suggest a battery tender (as suggested above) and possibly consider the electric ignition down the road. I appreciated the honesty.

Here is a pic of my bike. I could not be happier! I had planned to buy something that needed more work but the price was certainly fair. The guy who sold it to me did all the engine and cosmetic work to have it back to original. The electrical was all original and in bad shape but gives me a few projects.

View attachment 71914

That's a beauty! Well worth any effort to get it up and running. This is another good airhead site as well. https://advrider.com/f/forums/airheads.85/ . (I hope it's okay to plug another site). Cheers.

 

[dbrick]

That's a lovely machine!

 

[daz]

I would purchase an inexpensive Battery Tender and use it. Save the money on upgrading the charging system. The contactless voltage regulator is inexpensive as well. Enjoy the ride!

 

[67986]

71 R60/5 upgrades

Beautiful bike. I purchased my 71 R60/5 in 1994 with 54,000 miles. It now has 229,000. I did add an electronic ignition soon after purchase since I prefer to always have the ignition spot on when I am riding. Adjusting the points and timing is one of the fun things of having an Airhead. If you enjoy doing that adjustment then just stay with the points. The points work well, just need occasional maintenance.
I have the stock charging system. I ride in the Northeast with a heated vest and have never had a problem. I keep the bike on a battery maintenance charger all the time when I am not riding. I do keep my RPM's at 4,500 or more all the time and I do take longer all day 4-6 hour rides so the battery is recharged during my rides. Short around town rides at lower RPM's may not recharge your battery sufficiently.
The past summer I had to replace the wiring harness. Time and heat had just broken down the wires and I was only getting on and off contact in the electrical system.
You have a great bike. Enjoy your rides.

Adirondack Bob

 

[beemerphile]

One advantage of the stock charging system is that repair parts are abundant and cheap because they are so commonly upgraded for capacity. However, most of the upgraded systems are of the same general design as the original (the exception being EME's permanent magnet system). If you don't need the additional electrical capacity, there is little to gain. My only failures in 42 years have been a couple of rotors and a voltage regulator. I've seen some diode board failures as well. A modern regulator, a well mounted and grounded diode board, and an occasional check on the brushes, and you should be golden. Remember to disconnect the battery before you go peering under the front cover! This caution is removed only with the addition of the EME Ducati style system.

Regarding ignition, I have tried to miss adjusting points and I cannot. The ability to set and forget the ignition system was won me over. I went years with a CDI booster that took a lot of the coil current off of the points, and that indeed lengthened the service life, but a crank-timed (vs. cam-timed) electronic system is the ultimate solution for me. EME makes an optical system that works with Bosch style alternators and a hall effect system for the PM alternators. Either does away COMPLETELY with spark scatter from a bent cam quill or wear in the timing chain. If you managed to break the cam quill trying to straighten it (or more commonly, break the fragile balance weight attachment) then the crank systems become the easiest path out of the woods.

 

[toooldtocare]

One more,,,,,NICE BIKE. Enjoy it for a long time.