Spark Plug Questions

[spudmanRZV500]

Hi folks. I just have a few questions regarding the proper spark plugs for my '85 RZV500R. I bought the bike from Iconic Motorbikes and when it arrived at my home, it had NGK BR8HS plugs installed. The bike has run fine since I have had it, although I sense that it may be running a bit rich judging by the oil spray coming from all four pipe tips. I'm going to check the adjustment of the oil pump cable tomorrow. While the plugs aren't that desired "tan" color, they aren't overly black or fouled either. Anyway, my questions are these:

1. The only service manual I have is for an RZ500N and it calls for an NGK BR9HS plug. Does anyone know if the RZV500R actually called for the hotter BR8HS plug right from the factory?
2. I have a friend who owns a shop here in town who has a decent supply of NGK B8HS plugs. It was always my understanding that the "R" was just used to indicate that the plug was the resistor type. Is this true and if so, am I OK to run the non-resistor B8HS plugs?

Thanks in advance for your help!

[Mike Cichetti]

When I first got my RZ in 1985 I was getting some fouled plugs so I switched to the B8s, The R does mean resistor and I believe they are used as not to cause interference to the electrics. Never had any issues with them. I’m sure other members more knowledgeable than me can add to this. Hope this helps, Mike

[spudmanRZV500]

Thanks Mike! I'll stick with the resistor plugs then, as another member told me the same thing (that the non-resistor plugs may interfere with the electronics of the CDI, YPVS, etc.).

[lost1750GTV]

#1 - from past reading here, its my understanding that Japanese market (detuned engines) specified the 8, 9 for everywhere else. It does seem a fair number of others use 8's, perhaps they had/have no intention of riding hard, so see an advantage to what others might consider a "warm up" plug.
You might want to research reading spark plugs.