Spark Plugs

["Tom Brown" <tbrown@xxxxxxxxxxx>]

Ben:

Bosch 4418s work very well.  I've tried them.  I like them.  I don't recommend
things I haven't successfully used unless I say that I haven't used them.
Practically the entire BMWRT.COM community uses them and swears by them.  On
top of that, they're easy to find and cheap.

The fact that they have 4 conductors may or may not have anything to do with
why they work well in 1100 and 1150 engines.   I'm not hung up on conductors,
but I won't not recommend something just because it happens to have 1 or 2 or
3 or 4 conductors.  If it works, it works.

In the end, we (and that includes you, Ben) don't really know why things work.
We know only that they do or don't work.   The fact that you don't know that
the Autolites are standard, single electrode plugs tells me that you're
theorizing heavily here.

The only issue I have with these Autolight plugs is that they're difficult to
find nowadays and they're longer than the stock plugs which puts the end of
the plug really close to the piston.   I don't know if this is a problem or
not.

I mentioned the late, great Bob Lentini because he swore by them and holed a
couple pistons once.  I truly respect his pioneering spirit and focus on these
particular engines.  He, more than anyone else, caused me to really love and
appreciate these machines.   Still, for some reason, his pistons broke.  It
probably had more to do with his modified timing settings and choice of fuel,
but the longer plugs may have contributed.  I don't want to do anything that
might shorten the useful life of my bike.

A lot of people seem to like the Autolights.  I used them once, but couldn't
find them again, only the supposed Champion equivilents.   They are cheap, at
under $4, but not platinum or iridium.  New info has come out of this thread
that the plug is now available in iridium.   I'm sticking with 4418s.   I feel
safer using them because of the stock length and I like the way the bike runs
better than with stock plugs.

- -TB

>Date: Wed, 8 Jun 2005 14:27:14 -0400
>From: Ben Barkow <dr.ben@xxxxxxxxx>
>Subject: re: Spark Plugs; report on BKR 7 EIX (8)

>Multiple-electrode spark plugs, one of the great triumphs of marketing,
I believe. If one electrode is good, then seven must be WOW.

>As I understand it, multiple electrodes were introduced as a
contribution of low maintenance: with all that metal, your gap is never
much worn. The fits with the car-like maintenance which The Factory
envisioned for the Oilheads. Since there is only a single spark, the
multiple electrodes serve no ignition purpose except to shutter the
spark up.

>The single spark plug Oilheads obviously have some kind of spark
shortcoming, and that's pretty embarrassing with a centered electrode
in a four-valve head! The least sound solution would be multiple
electrodes and, again in my limited understanding, the best solution is
to buy those precious metal spark plugs that have tiny, carved away
electrodes which let the spark and the swirling mixture get as intimate
as possible.

>I removed the two-electrode stock recommended plug and installed an NKG
iridium (about can$20 each) BKR 7 EIX (8) about 1500 miles ago in my
1999 R1100S with a Techlusion 1031 and K&N filter (but I am no fan of
K&N). Took the first peek today: very mild tan tint but well within the
OK range. The bit of tan suggesting too much city driving, to much
richness and/or coldness but not much reason to change plugs or heat
range. I couldn't expect better running than I am getting, if that is
some kind of praise for the plugs.

>Denso makes really tiny electrode iridium plugs. Some platinum plugs
(the Autolites?) have carved electroduces too. The precious metal plugs
keep their gaps (that was their initial claim).

>Having said all that, I don't think plugs usually make much of a
difference in performance and their easy access to change generates
more discussion than they merit, within broad limits. Often a new sharp
plug is helpful esp. with a weak ignition. Often ANY change seems
helpful. And having said that, I'd recommend the Autolite plugs or
maybe the trick platinums or  iridiums. But for sure, not
multi-electrode plugs.

Cheers.

Ben

Ben Barkow, Toronto... 39 seasons on Beemers, 44 as a biker

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