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Correct spark plug for a 1983 R100
- Thread starter ksdcr
- Start date
The question would be which has more added resistance.
It changes as the rubber covering degrades over the years perhaps allowing rain/washing soap in or the heat of running. The changes are less when, like everything else, when rubber coverings are kept in a climate controlled environment. Tough to do.
Class A RV’s are known for “baking” the wires into submission. 8- 8” wires for the COP (coil on plug) system in my RV were DELCO and $165.00 IIRC.
An engine breaking down under load is a good indicator of wires going bad.
OM
For sure, a rough running engine could point to an ignition problem...could also be a carb problem. I'm sure the change in resistance that could cause this to happen isn't like 10-20 ohms, but more like thousands of ohms.
On the Airheads, there's a general check that can be done and has been offered by Matt Parkhouse and Oak Okleshen. We can measure the resistance from one spark plug cap all the way to the other spark plug cap. Using my /7 as an example, the caps are generally 5K ohms and each of the coils is also 5K ohms. So an end-to-end measurment should be on the order of 20K ohms. I think the gurus have suggested 20-22K ohms. It's clear that if a spark plug that added another 2-5K ohms each (I'm not sure what they are these days), that's more than just a simple linear resistance build up in the high tension leads.
On the Airheads, there's a general check that can be done and has been offered by Matt Parkhouse and Oak Okleshen. We can measure the resistance from one spark plug cap all the way to the other spark plug cap. Using my /7 as an example, the caps are generally 5K ohms and each of the coils is also 5K ohms. So an end-to-end measurment should be on the order of 20K ohms. I think the gurus have suggested 20-22K ohms. It's clear that if a spark plug that added another 2-5K ohms each (I'm not sure what they are these days), that's more than just a simple linear resistance build up in the high tension leads.
lkchris
Active member
I think the "disappearing from the market" thing is just marketing by American distributors who apparently believe all vehicles are like American vehicles. They are not particularly sophisticated.
One example is Bosch USA, which might as well be a separate company from Bosch Germany. They indeed sell nothing but resistor plugs. They in fact sell almost nothing from Germany.
The Euromotoelectics find posted above is a good choice. He is an informed seller ... which is rare.
For correct Bosch plugs, see your BMW dealer--their plugs are sourced from Germany, not Broadview, Illinois.
It's good to understand that living in the USA doesn't mean you live in the ultimate place for automotive parts. The USA imho is a third world country when it comes to things automotive and our auto parts dime stores have virtually nothing for owners of German motorcycles or cars. It is possible to source genuine name brand tube type (not tubeless) tires for Airheads, but you'll be personally importing them from Europe. I once imported via MotoBins tube type TKC80 tires in 3.00x21 and 4.00x18 for my G/S. Neither were available from USA sources. I'm not so certain mounting of tubeless tires on Airheads (with or without tubes) is even legal in Germany for '84 and earlier bikes.
Do it yourself tire service basically ended with tubeless replacing tube type tires. Have you experienced mounting a tube type tire on your Airhead? On my G/S it was almost possible using no tools at all. As you all know it's no fun mounting tubeless tires on snowflakes. K-bikes came with plug kits and CO2 bottles, not tire tools and patch kits.
In 2023, owning an Airhead is owning a "historic" or "vintage" bike and expectation of easy USA parts availability everywhere is dubious. Good to have European sources.
One example is Bosch USA, which might as well be a separate company from Bosch Germany. They indeed sell nothing but resistor plugs. They in fact sell almost nothing from Germany.
The Euromotoelectics find posted above is a good choice. He is an informed seller ... which is rare.
For correct Bosch plugs, see your BMW dealer--their plugs are sourced from Germany, not Broadview, Illinois.
It's good to understand that living in the USA doesn't mean you live in the ultimate place for automotive parts. The USA imho is a third world country when it comes to things automotive and our auto parts dime stores have virtually nothing for owners of German motorcycles or cars. It is possible to source genuine name brand tube type (not tubeless) tires for Airheads, but you'll be personally importing them from Europe. I once imported via MotoBins tube type TKC80 tires in 3.00x21 and 4.00x18 for my G/S. Neither were available from USA sources. I'm not so certain mounting of tubeless tires on Airheads (with or without tubes) is even legal in Germany for '84 and earlier bikes.
Do it yourself tire service basically ended with tubeless replacing tube type tires. Have you experienced mounting a tube type tire on your Airhead? On my G/S it was almost possible using no tools at all. As you all know it's no fun mounting tubeless tires on snowflakes. K-bikes came with plug kits and CO2 bottles, not tire tools and patch kits.
In 2023, owning an Airhead is owning a "historic" or "vintage" bike and expectation of easy USA parts availability everywhere is dubious. Good to have European sources.
88bmwjeff
SF Bay Area
Going to the 80/20 rule in that 20% of the products of a company results in 80% of their income. I came to realize that as companies consolidated and went to mega stores, the products they sold were only in that 20% area. As such, if you needed something in the 80% balance, you were hunting high and low for that item. As an example...before Home Depot and Lowes, there were a few screw and bolt shops that had just about anything you needed. When Home Depot and Lowes opened up they had that 20%, but not that 80%. Since most people went to Home Depot or Lowes for bolts and screws, the screw and bolt shops went out of business. But, now if you have something that's not in that 20%, it's more difficult to source. This can be said about a lot of other areas.
?
Reasonably priced non-OEM replacement parts are working great on both my Mercedes AND airhead. A turbo Mercedes is complicated and OEM replacement parts are often obscenely expensive, while the airhead is quite honestly about as sophisticated as a lawn mower. If eBay or lawn mower parts fit either, I’ll use them. In my experience, German parts are of no better quality than those sourced from elsewhere, based on experience on longevity of the originals.
BRICKRIDER
BrickRider
Correct Spark Plug for 1983 R100 /7
I have an original paper BMW Parts "Auxiliary Catalog" for BMW R100 - R100RT. The two spark plugs listed for that engine & year are the Bosch W5D and the Champion N6Y. From there it gets fuzzy as a current cross reference chart does not show either one as current production. An NGK BP6ES is the equivalent of a Bosch W6D - close but no cigar. The Bosch W6D was used on Models 1978 and older. I presume they went to the W5D as a result of the changeover to electronic ignition.
If you have the original ignition wires & caps, or an OEM replacement of such, best is to stick with the NON-resistor type plug. Since my cross-reference list does not show the W5D, I have no way to interpolate what an NGK equivalent might be. A BP5ES = Bosch W8DC, so guessing for the W5D equivalent is futile. My chart does not show a BP7ES. I have a box full of NOS R100 parts for 1981 & newer laying around but no spark plugs in there.
Best I can do, but your question was probably already answered elsewhere in this thread, as I did not read all of the posts. - BrickRider
I have an original paper BMW Parts "Auxiliary Catalog" for BMW R100 - R100RT. The two spark plugs listed for that engine & year are the Bosch W5D and the Champion N6Y. From there it gets fuzzy as a current cross reference chart does not show either one as current production. An NGK BP6ES is the equivalent of a Bosch W6D - close but no cigar. The Bosch W6D was used on Models 1978 and older. I presume they went to the W5D as a result of the changeover to electronic ignition.
If you have the original ignition wires & caps, or an OEM replacement of such, best is to stick with the NON-resistor type plug. Since my cross-reference list does not show the W5D, I have no way to interpolate what an NGK equivalent might be. A BP5ES = Bosch W8DC, so guessing for the W5D equivalent is futile. My chart does not show a BP7ES. I have a box full of NOS R100 parts for 1981 & newer laying around but no spark plugs in there.
Best I can do, but your question was probably already answered elsewhere in this thread, as I did not read all of the posts. - BrickRider
BRICKRIDER
BrickRider
Plug for R100
Yup. Who has not seen lawn & garden equipment run just fine with the "wrong" plug in it? I am no electrical engineer, but my guess is that the plug will start to give less than optimum results at an accelerated rate as it nears the end of its service life. Careful observation will tell you when that is. If I were in your shoes, I would regard the NGK plugs as cheap enough to replace at, say, about 5,000 miles, or perhaps whenever you do valve adjustments according to the book.
I had a 1983 R100RT purchased in late 1984 with 8,000 miles on it. It had been ridden for 2 seasons with no maintenance whatsoever. Tires bald, oil black as Texas Tea, valves practically closed up, one carb leaking, etc. When I sold it in 2000 it had 125,000 miles on it and never left me stranded. Rode most of the lower 48 with it. Found out the hard way the meaning of the famous moniker for the seat - "Vinyl Covered I-Beam". Did most of my own maintenance. Since I often rode it hard & put away wet, wear & tear on the parts was way more than most other bikes for comparable mileage. Valve job required like clockwork every 40,000. After the first valve job closed off & removed those stupid pipes that injected air from the airbox into the exhaust area of the head and turned the exhaust valves & seats into lava. Had one of the famous crappy Werle (sp?) diode boards that got hot and failed because solder turned to liquid & flowed all over causing short circuits. My brother's 1982 R100RT came with a Bosch diode board that never failed. Then there was the famous defective alternator rotor that failed in the Appalachian Mountains. Managed to limp home by unplugging the headlight and stopping to charge the battery often. As I recall, a guy named Rick Jones (hope I remember correctly) rebuilt that one for me. When I showed the rebuilt unit to my brother (repair tech at Delta Airlines) he said the work was of aircraft quality. And it never failed again.
I could go on, but all this to advise moving forward to not sweat the cost of replacement of parts on this model bike. If it is broken or about to wear out, just replace it and get back to enjoying the ride rather than spend too much time fixing or "trying to make do". Oh, and make sure to carry with you on the bike a spare carb throttle return spring and spare carb choke return spring. A dozen doughnuts says that 9 of 10 dealers do not stock these items. If one breaks on a Sunday afternoon 1800 miles from home and 10 miles West of BFE, as happened to me, the fix was measured in minutes, as opposed to days....
- Brick
Yup. Who has not seen lawn & garden equipment run just fine with the "wrong" plug in it? I am no electrical engineer, but my guess is that the plug will start to give less than optimum results at an accelerated rate as it nears the end of its service life. Careful observation will tell you when that is. If I were in your shoes, I would regard the NGK plugs as cheap enough to replace at, say, about 5,000 miles, or perhaps whenever you do valve adjustments according to the book.
I had a 1983 R100RT purchased in late 1984 with 8,000 miles on it. It had been ridden for 2 seasons with no maintenance whatsoever. Tires bald, oil black as Texas Tea, valves practically closed up, one carb leaking, etc. When I sold it in 2000 it had 125,000 miles on it and never left me stranded. Rode most of the lower 48 with it. Found out the hard way the meaning of the famous moniker for the seat - "Vinyl Covered I-Beam". Did most of my own maintenance. Since I often rode it hard & put away wet, wear & tear on the parts was way more than most other bikes for comparable mileage. Valve job required like clockwork every 40,000. After the first valve job closed off & removed those stupid pipes that injected air from the airbox into the exhaust area of the head and turned the exhaust valves & seats into lava. Had one of the famous crappy Werle (sp?) diode boards that got hot and failed because solder turned to liquid & flowed all over causing short circuits. My brother's 1982 R100RT came with a Bosch diode board that never failed. Then there was the famous defective alternator rotor that failed in the Appalachian Mountains. Managed to limp home by unplugging the headlight and stopping to charge the battery often. As I recall, a guy named Rick Jones (hope I remember correctly) rebuilt that one for me. When I showed the rebuilt unit to my brother (repair tech at Delta Airlines) he said the work was of aircraft quality. And it never failed again.
I could go on, but all this to advise moving forward to not sweat the cost of replacement of parts on this model bike. If it is broken or about to wear out, just replace it and get back to enjoying the ride rather than spend too much time fixing or "trying to make do". Oh, and make sure to carry with you on the bike a spare carb throttle return spring and spare carb choke return spring. A dozen doughnuts says that 9 of 10 dealers do not stock these items. If one breaks on a Sunday afternoon 1800 miles from home and 10 miles West of BFE, as happened to me, the fix was measured in minutes, as opposed to days....
- Brick
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