Spark plugs - resistor plugs

[ghebert4189]

Good morning,
I'm looking for any insite on spark plugs for a 1971 280 SL. My mechanic recommends using non resistor spark plugs, but I am having real hard time finding any. Is anyone using the resistor plugs in their 280 SL's, and if so are you having any issues? Also, can you mic plugs with some being resistor and some the old solid state? Lastly - anyone know where I can get some of the solid state plugs?

[Cees Klumper]

NGK BP7ES would be a good start as far as heat range, available from various suppliers. These are non-resistor.

[Benz Dr.]

NGK BP7ES would be a good start as far as heat range, available from various suppliers. These are non-resistor.

I used to use BP5ES but they're no longer available through my normal sources. We found some AC plugs that are non resistor so will see how they work. Resistor plugs have at least 5K ohms of resistance which you don't need.

[ja17]

Finding non-resistor plugs is becoming a real problem these days. I heard that Bosch began suppling them again, special order, but are very expensive ($12.00 ea.?) from Mercedes. You use a MB part number and order at the dealer. Otherwise, if you had an old original non-transistorized ignition and upgraded your ignition to a hotter coil and ballast resistor, your probably fine with a resistor spark plug. It's best to use non-resistor if possible. I also heard that the old Champion 7YC, non-resistor, copper core plug is still available?

[mdsalemi]

Good morning,
I'm looking for any insite on spark plugs for a 1971 280 SL. My mechanic recommends using non resistor spark plugs, but I am having real hard time finding any. Is anyone using the resistor plugs in their 280 SL's, and if so are you having any issues? Also, can you mic plugs with some being resistor and some the old solid state? Lastly - anyone know where I can get some of the solid state plugs?

I use BP6ES and when they started becoming scarce last year, bought up a lifetime supply from all the local suppliers. I would NOT mix resistor/non-resistor...
You can probably find some non-resistor on eBay...

[zoegrlh]

I did the same as Michael, bough up all the Bosch plugs I could find when they stopped making them. However now I am running NGKs, as Joe suggested and put in for me at the PUB Virginia. They run really smooth, I’m sold on them, but still have the Bosch in safe keeping.

[franjo_66]

there are still NGK BP5ES available if you scour ebay and vendor sites. I bought 50 of them from rockauto.com as they are also used in my 560SEC and BMW E23 735i

I personally think the BP7ES are a bit too "cold" for our engines.

[Benz Dr.]

there are still NGK BP5ES available if you scour ebay and vendor sites. I bought 50 of them from rockauto.com as they are also used in my 560SEC and BMW E23 735i

I personally think the BP7ES are a bit too "cold" for our engines.

They are, although it's what's called for.

[Cees Klumper]

Motivated by this thread I checked the condition of my BP6ES plugs yesterday, and noted that they were getting too hot. So I am ordering BP7ES to try. Very plentifully available here in France on Amazon.
Will also check ignition timing (although that should be spot on) as incorrect timing can also cause plugs to run too hot. I don't think it's running lean, judging from my 19 MPG consumption.

[neelyrc]

On NKG.com they indicate that the 7832 BP5ES has been discontinued which we have known for some time.  They recommend NKG 7734 BPR5ES as a replacement.  Has anyone tried these plugs.

I see limited numbers of 7832 plugs still offered on the internet in Italy but at extremely high prices.

[badali]

W7DC are available now.  Just do an internet search.  They are about $3 each depending where you buy them...

[Vander]

On NKG.com they indicate that the 7832 BP5ES has been discontinued which we have known for some time.  They recommend NKG 7734 BPR5ES as a replacement.  Has anyone tried these plugs.

I see limited numbers of 7832 plugs still offered on the internet in Italy but at extremely high prices.

Do not use those, the 'R' in them signifies resistance.