Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board I bought the wrong plugs but are they usable?

I accidentally bought a whole bunch of NGK BR8ES thinking they were BP8ES. What’s the difference between the, can I still use these?

The BR8ES are 5k ohm resistor plugs, the BP8ES plugs are not. Depending on what kind of ignition you have, they may or may not be happy in there....

Lannis

My understanding is that the initial BR code indicates a plug with a resistor built in so you probably dont want to use plug caps which already have resistance built in or the spark will be weakened.

The BP prefix suggests a projecting insulator type which is used to get the spark deeper into the cylinder.

So using a BR plug may work but the spark wont be as far in the cylinder.

Have a look at the chart Here for an explanation of the plug numbering.

Considering our bikes never came with a projected tip you’ve probably done the better thing without realising it. The resistor in the plug won’t cause an issue with ei or points, just try to ensure your caps don’t have resistors in them also.

I could be wrong but I think the BP8ES have been discontinued?

Short answer is yes. The R stands for built in resistor. Some high tech ei systems require resistors but not if you have the run of the mill Boyer or Pazon. Seems like NGK is phasing out non-resistor plugs. For what it's worth I've used both types in the same bike with Pazon Surefire ignition(doesn't require resistors) and non resistor caps and can't tell any difference. The P stands for projected tip. The tip extends further into the combustion chambers. Don't use them in a BSA but they are specified in Norton Commandos.

NGK has discontinued non resistor plugs. To make it worse, I believe the r plugs have non removable caps so they won't fit the plug caps on half of my bikes

Luckily my local napa told me when this was happening so I was able to order all the plugs in the midwest in the sizes i need.

I've actually had to turn the non removal caps down and install grooves using my lathe and a tool post grinder to get the plug I wanted for use with coil over plug caps...not for a British bike but it is possible if the need arises. Of course, I ruined one plug trying to remove the non removable cap and then another by trying to machine the cap before I went to the grinder...live and learn...Mark R.

Interesting
Non Resistor plugs are still available down here.
My mower suppliers still list BP 5's , 6's , 7's & 8's
Just for the heck of it I added a box to the order I put in yesterday and it showed them to be in stock.
So was it really NGK stopping supply or just Napa deciding not to stock them ?

Its NGK. I know people here that ordered standard plugs shown in stock and got the resistor plugs.

Something wrong with using Champion N3?

Hi Trevor,
Here too. Increasing majority of vehicles needing OE HT resistance to avoid screwing up various electronics, maybe a US NGK bean-counter calculated the cost of warehousing slower-turnover non-resistor plugs was costing 'em too much?

Regards,

Resistor plugs were first marketed in the US around 1950. I believe by 1970 all US vehicles with perhaps the exception of heavy trucks were using resistor plugs as original equipment... Yes, it's either a stocking issue or a violation of some obscure emissons law.
Some new n/a two cylinder street bike engines are making near 200 hp per liter out the factory door most likely with supressed wires and plugs...The ignition system in an old Brit bike firing a fat mixture with far less cylinder pressure has an easier job... An ignition in good good condition should have no issue with resistor plugs...

I’ve used the NGK BP8ES for years! What’s the best non resistor replacement for them?

Champion N3's work for me.
SteveG

Nothing wrong with NGK BP8ES or Champions N3, N4's

We all have our sentimental favorite. For me my go-to plug has always been: Nippon Denso W24ES-U.
What's the "-U" all about you might ask? Why that's the patented ND "U" channel in the negative electrode that provides for a "fatter,
more all-inclusive " spark to ensure total ignition of those pesky fuel vapors present in the combustion area...an ND exclusive to provide
that racer's edge over the competition....!

I only tried the ND 'hot U' plugs once, when the shop put some in my Trident during a tuneup. Maybe he got the wrong heat range, but it didn't run right until I put in some N3s.
The A65 likes NGK, the Triumphs prefer Champions. Of course, my old VWs liked only Bosch plugs. The BMW doesn't seem to care, so I put NGKs in it. The K uses both resistor plugs and resistor wires. I'm not gonna confuse that computer.