Topica Loopframe_Guzzi Archive


Subject: RE: Spark plugs -- Bosch rep blowing smoke?

Author: Chuck Sherman

Date: Feb 2, 2005, 2:33 PM

Post ID: 1718322829



I've heard the same re: plats; I'm runnin' +4's in my Dnepr and a stock
ignition set. The points do burn, but this I chalked up to poor russian
electrics.

The issue us not load; rather it is longevity of the point set which is
supposedly the issue. I'm not an EE, but I think it has to do with the
summation of resistance; I was under the impression that resistor plugs
and caps increased the resistance of the ignition circuit so as to
suppress radio interference. This, in turn, increases the overall
ignition system resistance which leads to arcing across the point gap.
Eventually the arcing cooks the points.

This is all supposition on my part; I'm a thermodynamic/mechanical kinda
guy. Heat flow/fluid flow I know; me and a Simpson 260 are a dangerous
combo.

William F. Dudley Jr. wrote:
 
"too much load on . . . ignition system" ?

This sounds like the Bosch rep is blowing smoke. I can't see how
anything but the coil/condensor impedance and the dwell angle would
affect the load on the ignition system.

In other words, the electrode material is not going to measurably
affect the ignition primary circuit, hence the ignition current drain.

Bill Dudley
Electrical Engineer
72 Ambassador owner


 

In a recent post Patrick mentioned the success he was having with Bosch
4216 platinum plugs. I use Champion RN9YC, but when I called my Bosch
agent with a view on a comparison he felt that the platinum tips and
even silver were too much of a load on old type ignition systems.It was
felt that the Bosch WR7C (plain copper) would perform as well with less
load on the eletrical system.I don't have a plug fouling problem with
any of the bikes or cars but just in case I was going to get a box. Any
thoughts?
Dorien

1967 V700 61 Falcone 71 Falcone 71 Stornello

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