Spark plug help - Do I need non resistive?

I’m gonna be changing the oil soon on my newly acquired 1980 XJ650 Maxim so figured I’d do the plugs as well. I’ve been doing tons of searching on here about spark plugs and it seems the ones I need would be NGK BP7ES. From what I read I guess NGK is doing away with (or did already) the BP7ES and replacing with BPR7ES. I don’t know much about this stuff but from what I read if I have the stock coil/wires with resistive caps I shouldn’t use a resistive spark plug. I can’t find the BP7ES at my local advanced they only had 2 left. I have 2 questions..

1. Do I 100% need to get non resistive plugs? If so can someone list a few good/popular alternatives? Would be nice if I could get them from Advanced Auto, Autozone, or Amazon so I can get them quicker but it’s not the end of the world if I have to wait. I’d prefer to get “better” plugs.. assuming there are some not so good brands out there.

2. It would be nice if I could change the wires but from what I’m reading it looks like the wires and coil are one piece. I know there is a splice kit available but I’d rather not have to deal with that. Does anyone make coils and wires that are literally “plug and play”.. aka just remove the old ones and put the new ones in without having to mess with cutting the stock coil or splicing wires?

Thank you!

 

1. No, not 100%. By using resistive plugs you'd be adding 5k Ohms of resistance, which could make a weaker spark, theoretically, but it will work. Adding more resistance for our 40+ year old ignition coils to overcome isn't ideal, but it will work.

2. Len (Chacal) sells aftermarket ignition coils with wires and non-resistive boots attached, so that you could use resistive plugs and have the right circuit resistance throughout. I just bought his "high output" ones, and they were not quite plug-and-play, but very easy to install and are working great. Here's the item (also available with red, blue, and yellow wires)

HCP22085BLK This kit comes complete with black 8mm plug wires already installed; wires have black non-resistive plug boots installed. Since these plug boots replace the use of the stock resistive plug caps, it is recommended that you also purchase a set of resistive spark plugs (XJ650 and XJ750 models should use the HCP13513 standard resistive plugs or the HCP1293 hi-performance iridium resistive plugs, and XJ900 models should use the HCP1295 standard resistive plugs or the HCP13515 hi-performance iridium resistive plugs (spark plugs are not included with this kit). Fits all XJ650, XJ750 air-cooled, and 1983-89 XJ900 models.
$ 289.95

 

Thanks! I will look into the kits he offers then. For now do you know which spark plugs I can use? Seems hard to find non resistive ones like the NGK BP7ES.

 

Check here:
https://www.weeksmotorcycle.com/spark_plug.html#gsc.tab=0

 

I run Honda CB750 coils these can be bought new and mount in stock location and have replaceable plug wires . These cost around 45$ each , you can find them on eBay or Cycle Recycle part 2 . I use Autolite 63 plugs these are equivalent to the NGK .

 

Question on the resistive plugs.... Do I have to get new plugs boots to fit these since the plug cap/tip does not screw off like on the original NGK plugs, leaving just a threaded tip on the plug..?

 

Are you sure they don't unscrew? They do on the NGK R plugs I've used.

 

yeah, I tried but it wasn't the NGKs, maybe I'll get those and give it a try....

 

with non resistor plugs becoming hard to find(xj4ever has them) you can change the value of the resistor cap to compensate and fit the plug