NGK BR6S

[Bryan Janeway]

Good day and thanks for reading,

Went to NAPA early this year and picked up new plugs. They didn’t have 4 of my usual champion RJ12C but they did have 4 NGK BR6S. It was on the compatible list so no problem. Everything good early on but engine began running rough. Checked plugs and #1 really fouled. Did the pull the ignition lead while running and clearly #1 not banging. Pulled lead out of distributor and I could get the plug popping at a certain spot but couldn’t secure it at that location. Got a little sparky thinking I might be able to . Had a spare distributor and rotor on board so thought I change those and it worked. Got out on the bay sailing and when trying to anchor at next spot clearly I didn’t fix anything. #1 still not sparking was able to nurse it in but blah. Left the anchorage this morning and while sailing to next spot thought to stick one of the old plugs in the #1 hole. Would have changed leads but didn’t have any. Problem solved ran the engine for about an hour and it was back to its singer sewing machine status…..

Kinda looking for some more understanding. The NGK plugs on the other three cylinders seem good?? Could it be one plug or is it the one lead?? How would I check the plug or the lead for damage or continuity???…

I’ll purchase some new leads just to have on board. Wondering if I should just put last years champions back in?? Or hit four Canadian tires and get four new champs. No one seems to have more than one

Thanks and any advice would be great.

Bryan

[Dave Neptune]

Bryan, you are describing a classic "bad plug", not real common but they're out there. If you had a good spark from that wire it has to be the plug.

If you wish to confirm just switch it out with another cylinder. If it follows the plug !!BINGO!!

Dave Neptune

[Bryan Janeway]

Good thinking. I’ll do some experimenting back to the dock tomorrow.

[ArtJ]

I have used the NGK BR6S for many years. In fact they were carried
by the original Moyer parts person.

I have used NGK plugs in my cars, small yard engines and outboards
\All with excellent resukts


Art

[Bryan Janeway]

Hello again,

Still having some issues. It seems to be clearly plug related. As suggested I swapped the “bad” plug into other cylinders and the problem followed the plug. I left the old Champion plug in the #1 cylinder figuring leave what was working. After a five hour run the rough running engine problem reoccurred with the champion plug. I installed a brand new NGK in the #1 hole and the problem went away. Again I did another couple of days without a problem (approx 10 hours on the engine). Then after a great sail started engine up to dock and I was back to rough running engine.

My trouble shooting was swap out the #1 ignition lead…. No change
Swapped out the coil…. No change
Swapped out the #1 plug for a new HGK…. Running fine now.

The only significant thing I’ve changed prior to this nonsense is over the last few years there was always black soot on the hull at the exhaust. The number 4 cylinder plug usually seemed more fouled than 1,2,3. It would run rough occasionally but after getting warmed up and into gear the rough idle would go away. I leaned the idle by about 1 turn and leaned the installed high end by one half turn. That stopped the black soot on the hull almost immediately and didn’t foul #4, and didn’t seem to have an effect on the running or acceleration of the engine. Besides the three burned plugs….

I have adjusted the mixture back to where it was and the engine is running fine now. I used the Moyer mixture setting procedures and richened that up to where it is now which is slightly rich on both high and low.

Does any of this make sense??

I can’t imagine that I can kill three plugs in two months by that small of a change in mixture settings.

Currently I’m good to go but if I kill another plug I will be extremely confused.

Best regards,

Bryan