Wrong plugs in my Seca 750

Just made an interesting discovery. I was getting ready to do a carb sync on my '83 Seca 750, so I pulled all the plugs to take a look before I started. When I went to reinstall them, I realized that they are the wrong plugs! Instead of the stock BP7ES, they are BPR5ES. Can't believe I didn't notice that before. I am guessing those are the plugs that were in it when I bought it 15ish years ago and I didn't think to look up the spec.

Not only are they the wrong heat range, but they are also resistor plugs. The bike still has resistor caps, so that's not right.

Caps are a little funky in their resistance measurements.

#1 = 8.5 k
#2 = 4.6 k
#3 = 4.6 k
#4 = 7.5 k

2 and 3 are in spec, but 1 and 4 are a bit off. Especially #1. Combined with the resistor plugs, that could be part of the reason I have trouble getting a smooth idle out of it.

I ordered the correct plugs. Might as well wait until the get here to do the sync.

Looking at the plugs, #1 looks a little sooty compared to the rest. The others seem a tad lean to me. Not sure I trust the appearance with them being the wrong heat range though. I'll have to check again after I get the new plugs.

#1

#2

#3

#4