Is there a better spark plug for the ss 107 motor than what the manual calls for?
S&S 107 spark plug
- Thread starter Big dog papa
- Start date
SHOW ME YOUR SPARK-PLUGS
That's what happens when you use Harley plugs:rolleyes:
www.bigdogbiker.com
Jersey James
Jersey James
I just use the cheap old reliable Champion ~ RN12YC. Never had a problem...ymmv
I had a good laugh going thru that old thread. You guys crack me up... 'pipe bomb'...
Are you saying; same heat range, but a different brand? Or are you saying a different heat range? If you buy a new vehicle, and no matter the state, book calls for the same plug. The heat range did not change from state to state. It means, that spec was covering all the ambient changes and came away with the overall performing plug.
I doubt HD has their own plug business, but uses a jobber like Champion to go over the bike with them and come away with a heat range that won't melt the engine, basically. Short of a radio frequency plug, if you looked at the porcelain bodies, they probably are the same plug heat wise.
Too little pour = Less Heat Made ~ Carbon build on the porcelain.
Book Spec = OL Performance ~ Clean white/tan tips.
Too much pour = More Heat Retained ~ Knocking on the door of the kinetic meets spark to arc gray matter [dots of aluminum] on the porcelain, and a tiny crater where the plug meets the dome of the piston.
I would stay stock or the field test that JJ came away with.
Are you saying; same heat range, but a different brand? Or are you saying a different heat range? If you buy a new vehicle, and no matter the state, book calls for the same plug. The heat range did not change from state to state. It means, that spec was covering all the ambient changes and came away with the overall performing plug.
I doubt HD has their own plug business, but uses a jobber like Champion to go over the bike with them and come away with a heat range that won't melt the engine, basically. Short of a radio frequency plug, if you looked at the porcelain bodies, they probably are the same plug heat wise.
Too little pour = Less Heat Made ~ Carbon build on the porcelain.
Book Spec = OL Performance ~ Clean white/tan tips.
Too much pour = More Heat Retained ~ Knocking on the door of the kinetic meets spark to arc gray matter [dots of aluminum] on the porcelain, and a tiny crater where the plug meets the dome of the piston.
I would stay stock or the field test that JJ came away with.
What we're saying is, the engineers that designed this engine wanted an RN12YC in this engine for it to perform property. Why doubt them.
DynoDave
Guru
Yep, you're not going to gain anything by going with expensive hyped plugs.
Here's a look at my plugs. To me they don't look hot enough or running too rich. The darker one is the back cylinder
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Left plug ~ it's shinny wet. That means ring or guide failure. Check compression on both cylinders and match comp's.
Right plug ~ it's a little dryer, but on the verge of going oil foul. Plugs should have a white/light tan porcelain if well jetted and high in compression.
Huston, we have a problem.
Right plug ~ it's a little dryer, but on the verge of going oil foul. Plugs should have a white/light tan porcelain if well jetted and high in compression.
Huston, we have a problem.
By the looks of the outside, I'd say they have been in there a while. Plugs are cheap, change them each spring. You can do a compression test if you want, but I'd change them out, ride it a few miles, pull and reaccess the situation.
Thanks for the info. I bought a new set today .I'll take your advice. Thx again.
knothead
Second Chance Customs
RN12YC Gap .038
This is straight from the BigDog manual. S&S one type / TP Engineering another.
john sachs
Well-Known Member
I've done a bit of A-B dyno testing with quite a few different brands of spark plugs. NEVER any difference after a few pulls, other than a liter wallet. Occasionally a slight timing change will take the plug that may have been a touch low, and bring it back even with the others. Ain't NO magic in the plugs if the gaps, timing, and fuel mixture is correct.
John
Now wires are a different subject.
John
Now wires are a different subject.
Good info.. Thx John.
DynoDave
Guru
What are the magic plug wires?????
john sachs
Well-Known Member
Any that aren't "Glitzy", light up, or braided steel encased. In other words a QUALITY STOCK type wire. Some fuel injection systems require a specific wire type. DON'T deviate.
John
Hey papa, because your new here, just throwing a FYI at you. We consider John a god, when it comes to engines.
I got to meet John at the River Grille get together. I don’t think I ever enjoyed a conversation with anyone so much.Hey papa, because your new here, just throwing a FYI at you. We consider John a god, when it comes to engines.