Bosch spark plugs for motorcycles??

 Hi All,

Does Boshch manufacture these at all?

Where can equivalences to other manufctures (like NGK) be found?

Thank you,
Big Ben,

 
BigBen wrote:

You can get Bosch at Auto Zone and (I think) Pep Boys.
They are the recommended plug for BMW motorcycles.

For plug equivalents, a quick google search turns up
http://www.spark-plugs.co.uk/pages/technical/

 
BigBen wrote:


Yes. I found the AC, Champion, NGK, Nippon Denso, and Bosch numbers for
my spark plugs here:

http://www.autosino.com/catalogue/sparkplug/

 krusty kritter wrote:

As a note, my BMW ran terribly on the recommended Bosch plugs - surging.
A switch to the Autolites made an enormous difference in improved throttle.

 
Paul Cassel wrote:


surging.

I have read that some BMW's seem to have a surging problem. This may be
a result of poor fuel *and ignition advance* mapping on FI motorbikes,
or it might be lean jetting and the advance curve on carburated
machines...

Or it just might be that the Bosch heat ranges aren't exactly the same
as the Autolites, which might run a tad colder---or at least the plugs
seem to act like it...

I noticed that when I switched from Autolites to Bosch plugs, my T-Bird
didn't ping on the recommended regular gasoline. I suspected that the
Bosch plugs were 1/2 a heat range colder than the Autolites, but it
could have also been a problem with the ECU's mapping...

Certain tuning conditions seem to go together. Hot engines with lean
mixtures or advanced timing will surge until they overheat and ping.
Cold engines with rich mixtures and retarded ignitions run lumpy and
carbon up...

Hot and cold spark plugs are supposed to solve some of the problems...

The spark plug manufacturers have to figure out just how long to make
the steel spark plug body so it will operate at just the right
temperature. And the electrode configuration does seem to make a
difference. A spark will jump from a cool sharp part of the electrodes
easier than it will jump from a hot eroded area...

But plugs that run too cold will foul, so the manufacturers have to
walk the narrow path between too hot and too cold...

I tried expensive gold palladium spark plugs that cost two or three
times what my standard NGK plugs cost. The NGK's were contantly
carboning up and would finally oil foul. The engine was a 2-stroke. The
gold palladium plugs were supposed to "work like a CDI ignition at an
extremely low cost". The center electrodes were very small. and they
couldn't reject the heat of combustion. The guy who recommended the GP
plugs said that I shouldn't worry when I saw the tips of the center
electrodes were actually melting!

Then somebody pointed out to me that the Nippon Denso "hot u" electrode
configuration seemed to run cleaner without melting. They look like an
NGK, but..

The hot u plugs have a center "ditch" in the ground electrode that
gives the spark more sharp, cold, clean points to jump to...

The engine ran so much better, it burned the fuel better, there wasn't
so much unburned hydrocarbons keeping the engine temperature cool. The
Nippon Densos *acted like they were 1/2 a heat range hotter* because
they burned the fuel so much better...

That big Suzuki 2-stroke triple had a fixed ignition system. It had to
run at whatever static ignition setting the tuner dialed in. Since the
ignition couldn't advance or retard, load on the engine and combustion
chamber temperature would determine whether it would surge or not.

If I was cruising at 70 mph and backed off on the throttle, it would
surge when the combustion chamber temperature rose just a bit. So I
would turn the throttle up and the engine would stop surging and
bucking, but it would accelerate. Soon I would be cruising at 90 mph
where it settled out under load...