The (R) factor?

Has anyone bought the NGK R BPR7ES spark plugs? Do you know what the R stands for?

 

resistor
if you have resistor wires, don't get an R plug
if you do... the opposite

 

If I had resistor wires what would happen if I put the R in ?

 

twice as much resistance than should be there
but I really have no real world experience here maybe someone else will add knowledge here

 

Longer burn time, weaker spark, maybe hard starting.

Fact is, you don't have resistor wires unless you've installed them yourself via coil surgery, or installed aftermarket coils. You do have resistor caps, though. OE calls for non-resistor plugs. In some places they are not available. In some places, or so I've heard, resistor plugs are actually mandated by law.

In most cases, resistor plugs seem to work just fine with the resistor caps. I'm guessing it doesn't make enough of a difference under well-tuned conditions. It might make a difference with other mods, and when things are less in-tune relative to factory specs (too rich or too lean).

 

My bad, I should of been more specific. I do have resistor caps on 2 &3 but not on1 &4 not sure why. Maybe by design ?

 

Mine are like that too. I think I use resistor plugs with the non-resistor boots.

 

I put 4 new resistor plugs in and went for a 25 mile ride, it ran good, took the plugs out and 1&4 were dry black and 2&3 were dry and black mostly, the white part was tan. ???

 

My bad on this post I should have said that I was in the process of dialing in the carburetors I had the air/fuel screws set at 2.5 turns out. When I went for a ride.

 

This is not by design. Design is 4.7K or 5K caps on all cylinders. They're different model caps, as the outer ones are 90 degrees and the inner ones are 120 degrees. Do you have original coils, or has the 1/4 been replaced at some point?

 

Original coils. My 83 Midnight maxim is the same.

 

My inner ones are 90 degrees also.

 

you can use non resistor caps and then use resistor plugs. that way you have refreshed the resistors when you replace the plugs.