Correct spark plug for a 1983 R100

[ksdcr]

Picked up a a pair of NGK BPR6ES plugs at the local auto zone. When I went to install them, noticed that the package says,
“Lawn & Garden”, and has an additional number, 6775.

Question is, will these be correct for installing into my 1983 R100?
Or should I go to my local BMW store, and get some?

 

[20774]

The "R" in the part number is for resistor. Generally, you should add resistance to the spark path...there's already a resistor in the spark plug cap. If there's too much resistance, the spark can be attenuated and the engine could misfire. I would find just the BP6ES instead. The newer number might be 7333.

 

[ksdcr]

Thanks.

I got confused by some of Snowbums comments on gapping.
Is 0.026 about right for the plugs?

 

[20774]

Sounds about right - 0.026".

 

[frankjarrell]

All airheads are stock with a non resistor plugs. The plug should not have an R in the part number. NKG no longer makes the non resistor plug so their cross reference list the resistor plug. Still a bit of old stock out there. You can still get the correct plug from stores that specialize in airhead parts.

 

[ksdcr]

All airheads are stock with a non resistor plugs. The plug should not have an R in the part number. NKG no longer makes the non resistor plug so their cross reference list the resistor plug. Still a bit of old stock out there. You can still get the correct plug from stores that specialize in airhead parts.

So I took the lawn mower plugs back. Auto zone guy could not find a non resistor that would be compatible with my airhead. Any specific places to get the non resister plugs?

 

[88bmwjeff]

Here you go

https://www.euromotoelectrics.com/product-p/bp6es.htm

 

[20774]

Napa??

 

[ksdcr]

Here you go

https://www.euromotoelectrics.com/product-p/bp6es.htm

Thanks. Must have had a senior moment, as I did surf through Euromotoelectrics site, and missed that.

John

 

[oldcamper]

eBay has NGK, Autolite, and other brands for about 5 bucks each.

 

[88bmwjeff]

FYI, the four digit number for the BP6ES plug is 7333

 

[ksdcr]

Thanks guys.

 

[52184]

eBay has NGK, Autolite, and other brands for about 5 bucks each.

Be very leery of NGK plugs on fleabay and Amazon—there are a lot of knock-offs, outright fakes, out there.

https://www.ngkntk.com/newsroom/blog/emea/fake-or-not/

https://www.diycarserviceparts.co.uk/blog/2019/09/19/how-to-avoid-counterfeit-ngk-spark-plugs/

https://www.youtube.com/watch?v=Lr9J3eQk-kE

Best,
DeVern

 

[ksdcr]

Be very leery of NGK plugs on fleabay and Amazon—there are a lot of knock-offs, outright fakes, out there.

https://www.ngkntk.com/newsroom/blog/emea/fake-or-not/

https://www.diycarserviceparts.co.uk/blog/2019/09/19/how-to-avoid-counterfeit-ngk-spark-plugs/

https://www.youtube.com/watch?v=Lr9J3eQk-kE

Best,
DeVern

I’ve had good success with Max, Euro moto, Hermy’s for pretty much anything.
In fact, when I was rehabbing this R100, EuroMotoelectrics sent me a large order of parts, but had included 32 carb bellows, instead of the correct 40’s. One phone call, and they overnighted the correct ones, and said keep the 32’s. I passed the 32’s on the a MacPac member.

 

[manitou_commando]

Make your resistor spark plug a non-resistor one

If you're unable to find non-resistor spark plugs, some of you may find this video helpful:

https://www.benzworld.org/threads/make-your-resistor-spark-plugs-a-non-resistor-ones.3041307/

 

[52184]

If you're unable to find non-resitor spark plugs, some of you may find this video helpful:

https://www.benzworld.org/threads/make-your-resistor-spark-plugs-a-non-resistor-ones.3041307/

Hhhmmm…no thanks. I’d not trust a plug that’s been modified that way, especially when it’s so much easier to just run resistor plugs and switch to non-resistor wires, or buy the Denso W20EP or W20EP-U from a local FLAPS. Denso is a quality plug in line with NGK, Autolite, or Bosch—and inexpensive enough to toss any time they are removed.

Best,
DeVern

 

[Omega Man]

I’m curious what difference in the actual running is between using a resistor spark plug vs non-resistor spark plugs?

Resistor plugs became a popular way to reduce RFI in car and 2-way radios back in the day. I have never found a difference in performance.

OM

 

[pglaves]

On Airheads OEM, the 5K Ohm resistance is in the spark plug caps. You can get non resistor caps. I found a set of 3 for $7 on ebay.

Then resistor plugs can be used just fine.

 

[ksdcr]

Found them at my local Honda dealer. Was told they are hard to get.

 

[20774]

I’m curious what difference in the actual running is between using a resistor spark plug vs non-resistor spark plugs?

It was my understanding that having too much resistance in the path to the plug electrode can reduce the strength of the "jump" of the energy to the ground electrode. So, if the bike has a marginally healthy ignition system, the result could be misfiring.