18 year old coils

[CanadianSteve]

Seems like a silly question, but I"ll throw it out there. My 1992 R100RS has the original stock coils ... over 100,000 miles, 18 years. Time to change them ? Upgrades possible or stock BMW parts ? Thanks for any input.
Steve

[Polarbear]

My '78 R100 has the original coils at 370000 miles, no issues. They are very simple and rarely break, bite my tongue, knock on wood! All the above miles are mine and the only bike in my life to live so long. I still ride her frequently. Randy

[60755]

http://www.motoelekt.com/

That's the go to site for most of us here in the states for anything airhead and electric.

Dyna coils are the standard aftermarket and reasonably priced at around $90usd

[osbornk]

Coils don't wear out. Like most electronics, they may quit today or last longer than the bike. My 86 bike's coils are still original and I think the coil is original on my 62 Fairlane.

[boxermaf]

I'd buy a Dyna coil from Rick at motorrad Elektrik - compact, last a very long time, and will likely give you at least 18 more trouble free years for less $$ than the BMW part. You could get a BMW OEM part too, of course. Coils do get warm, and the BMW coils (from the early 80s at least) tend to develop tiny cracks in the coil housing as it ages - letting in moisture and causing intermittent problems and/or smoking short circuits. Your coil may last another 100K miles, or it could fail completely tomorrow, or it might start giving intermittent problems this summer. Anything that is electronic has a half-life, does wear out from heat and environmental effects, and needs to be replaced at some point. I design industrial electronics for a living - I'd say you've gotten very good service from that coil, but don't expect that it will last forever.

[mneblett]

Coils don't wear out.

HOWEVER, if they are the original grey crack-o-matic OE coils, they develop hairline cracks. The cracks let moisture in, and the coils stop making pretty blue sparks in the boom-boom rooms.

The coils were the one of the first things I checked on my new-to-me '88RT, and sure enough, they were cracked -- I counted myself lucky that I did not have to undergo a water-intrusion test on the trip back from picking the bike up in Colorado -- perfect weather all the way back to VA.

SO, take a *close* look at your coils. The characteristic cracks are true hairline cracks, so look hard. The cracks on mine were on the side of the body, longitudinally oriented from front to rear.

Oh, and beware the slippery slope! Once I knew I had to replace the coils, the question was "should I get a coil I can use later with a dual plug set up? Well, since I'm contemplating that, it appears I need some valve guide work, so should I get the heads machined for dual plugs while they're off? And since I'm having the heads done, how much is a set of 9.5:1 pistons? And ..." Doesn't take long to get to the bunch o'$$$ stage!

[RonKMiller]

When I went through my '79 I took special note of all the electronic goodies - and even though everything looked good - I just decided to bite the bullet and replace the coils, plug wires and caps, along with cleaning all the connectors in the headlight bucket, etc. Tedious, but this way I figured I was starting out with a relatively "clean plate."

I took somewhat of a gamble and replaced the coils with new made in Brazil Bosch coils that were a bit longer than OEM but still fit great, plus they are nice and shiny. These are standard fare that can be picked up at any VW repair shop.

$35.00 each, (versus almost $100 for OEM?) although once again I may have screwed the pooch in the long run since I'm not 100% sure they have the exact correct output. I'm an electronics dummy, but I kinda figured 6V is 6V, and after all, it's an Airhead! We're not talking sophisticated electronics here...

The points and plugs still look good, it fires up on first tickle, so I think everything is nominal. From what I can glean these coils should ONLY be used on 1970 to 1980 models so beware! I believe it has to do with resistance.

[Darryl Cainey]

1977 R100RS 487,500 miles same stock coils.

If it ain't broke... don't fix it!

[88bmwjeff]

It seems that most say they don't wear out, but mine did. Although I have the grey Crack O matic coil, mine was not cracked. However, it was putting out a weak spark. When I replaced the coil, my RPM's increased. I don't remember the amount, but it worked out to about a 20% increase.

If you're not having any issues, don't worry about it.

[kwb210]

Motoelekt has this coil for the 1970 to 1980 airhead and notes no mounts. Has anyone that purchased one have a comment on the mounting? I am going over my bike this winter and coils are on the list to check.
Thanks!
kurt

""Green 3.0 $95 each with mounting bracket, $150 pair (no mounts)

GREEN coils have 3 ohms primary resistance, for points ignition systems and older dual-plug applications.

Use ONE coil for ALL MODELS made from 1970-1980 that came from the factory with POINTS ignition. Comes with single mounting bracket. Also good for use on /2 conversions with a 12 volt system.""

http://www.motoelekt.com/

That's the go to site for most of us here in the states for anything airhead and electric.

Dyna coils are the standard aftermarket and reasonably priced at around $90usd

[20774]

1977 R100RS 487,500 miles same stock coils.

Darryl -

~14.3K miles per year...that's pretty impressive!!

[GRAHAMM]

Seems like a silly question, but I"ll throw it out there. My 1992 R100RS has the original stock coils ... over 100,000 miles, 18 years. Time to change them ? Upgrades possible or stock BMW parts ? Thanks for any input.
Steve

My R100GS always starts up on one cylinder and then the other after a few turnovers.... original coils. I have purchased the motorrad Elektrik coils and will post if they and new wires bring life to the beast in balance faster.... I hope so... if that is not the issue fuel will be. I also purchased the diode upgrade and voltage regulator to ensure reliable charging. Did not go for the increased output alternator, the one I have seems to keep up with my electrical demands.

[68159]

My 78 R100/7 have the original coils and they are fine.

[rowens816]

6V volkswagen coils from Autozone @ $18 each. They seem to work extremy good. Same specification as original. Duh.

[RonKMiller]

6V volkswagen coils from Autozone @ $18 each. They seem to work extremy good. Same specification as original. Duh.

I would be surprised if yours ARE made by Bosch.

Autozone touts that it's coils are made by Wells - a "global supplier" - and we all know what THAT means: Probably made in China, hopefully made in Mexico or Taiwan. It's still garbage compared to genuine Bosch components.

For me, spending an extra $17.00 on a name brand coil recommend by an acknowledged expert in Airhead ignition (not me, certainly) is a no brainer if I have to risk being stranded somewhere - or worry about frying something REALLY expensive.

This brings up the fairly recent discussion of supposedly genuine BMW points - until it was discovered that the rubbing blocks would not even allow them to be adjusted at all since they were not even close to BMW specs. They were out and out fakes.

Coils do have very specific OHM measurements and vary dramatically among supposedly similar coils - from what I can tell this is VERY important.

All kinds of counterfeit cheap stuff out there. You pays your money and you takes your chances.