plugs

[Deathstar88]

what is the difference between NGK bpr5es-11 and bpr5es ? both have same numbers except for the -11. I put the regular plug without the 11 in my bike today and it runs fine. just wondering if I need the other model ending in -1 to run properly

 

[Mr. Wright]

If your 03 has the 107, which it should, this it straight out of the manual.
SPARK PLUGS
CHAMPION SPARK PLUGS, used as original equipment in all BIG DOG motorcycles, utilize a
patented semi-conductor resistor to substantially reduce radio frequency interference (RFI)
created each time the spark jumps across the gap of the spark plug. This RFI can result in
starting and drivability problems, loss of performance and can even cause the ignition system
module to completely shut down.
It is extremely important to use Champion resistor-type plug to ensure that the onboard computer
that is the basis of BIG DOG motorcycle’s ignition system, is protected from this RFI.
Do not rely on industry standard cross-referencing to find an alternative brand of spark plugs to
replace your CHAMPION OEM’s with. The replacement plugs may not be of a resistor-type.
Use only CHAMPION RN12YC in S&S motors and RA8HC in TOTAL PERFORMANCE
(TP) motors.
Spark plug gaps are both .040” and torque is as follows: TP: 14 ft-lbs
S&S: 18 ft-lbs

 

[Sven]

11 means the factory gap.
https://rb30det.com/wp-content/uploads/2015/07/ngkchart.jpg
http://www.turbododgeparts.com/assets/images/Plug-Chart-Champion.jpg

The porcelain heats up a lot more. So when you look down and see lots of porcelain heading down the plug, you can tell about the heat ranges. More porcelain, more heat retained. More heat retained, better to burn off the carbon buildup. Hot ranges are more for general use. Easy starting, longer lasting. A too cold plug with hardly any porcelain to see, this is for racing applications. This is hard starting and is not the best plug due to carbon build if street ridden and finally goes foul.

 

[Deathstar88]

thanks for the info. Can I gap it at under .040? at like .038?

 

[Deathstar88]

thanks for the info. Can I gap it at under .040? at like .038? I just bought a pair of Champions, and they came gapped out of the box at under .040

 

[Mr. Wright]

thanks for the info. Can I gap it at under .040? at like .038?

Yes, as a matter of fact, I run them at .038

 

[Deathstar88]

my gauge doesn't go down that low. lowest it goes is .040. So I went to .040 and tightened it up a little from there

 

[Sven]

Schools us both... no problem.

The deal with gaps are:
1. The narrower the gap, the longer you can extend its life.
2. The wider the gap, the wear opens the gap farther away from the two points and starts to find the shorter path and begins to misfire.
3. The spark is always chipping off tiny molecules of metal you can't see with the naked eye, but down the road the 'side electrode' no loner has a sharp edge so the spark has an easier jump to the side electrode.

a. Say I drop a rock an inch off the water. How's my splash?
b. Say I drop a rock as high as a foot. What is my splash going to look like now?
c. Wouldn't a wider gap fire off more molecules and begin the flame-front sooner? Wink-Wink.

 

[Nukeranger]

Dropping a rock from different distances has nothing to do with how many molecules fire off!

 

[bigkelk9]

Easy there huw, lol, good point though, but I’m still a firm believer in champion plugs on these things

 

[Jersey Big Mike]

Dropping a rock from different distances has nothing to do with how many molecules fire off!

He was trying to draw an analogy to the change in power A(gap distance/spark intensity -- speed of rock/ft/lbs of force)
and the damage done to the spark plug/rock when more power is imparted. Even though the damage is undetectable to the human eye.

 

[pknowles]

He was trying to draw an analogy to the change in power A(gap distance/spark intensity -- speed of rock/ft/lbs of force)
and the damage done to the spark plug/rock when more power is imparted. Even though the damage is undetectable to the human eye.

That's exactly what I was thinking Mike

 

[Sven]

He was trying to draw an analogy to the change in power A(gap distance/spark intensity -- speed of rock/ft/lbs of force)
and the damage done to the spark plug/rock when more power is imparted. Even though the damage is undetectable to the human eye.

Close. Say the coil puts out 30k v at the gap. Widening the gap does not change the volts. It's more like, say I soak {pick an object} with a volatile liquid. I have a torching device and I now touch the soaked object in one spot. The flame front now heads down and up if I touched the center only. But if I dragged the flame from the bottom to the top, the flame front was a lot shorter touching those flammable molecules with the same 30k v, at the same speed of the spark, right?

Now, eliminate the object and replace it with fuel misted air. Did the wider gap fire off more surface and increased the flame front? Same goes with the rock and splash. Did more splash out of the pool/pond/etc., become more suspended in the air than an inch dropped?

You gotta think outta the box like JBM., and Paul