[Diy_efi] Iridium plug problems

[Tim Marsteiner]

Are you talking about the center electrode?

It comes brand new like this. A smaller/finer
electrode sparks easier (no, I don't remember the emag
equations that prove this). The iridium coating is
much harder with higher melting point allowing it to
be so fine.

I just went for a ride (picked up a fuel pressure
gauge) with new coils and new standard plugs
installed. No problems, but bike does not run nearly
as smooth.

Tim

--- Jim Butterfield <jimbutterfield at yahoo.com> wrote:

> that electrode tip on that left side plug is pretty
> corrodded... 
>  
> jim
> 
> Tim Marsteiner <tmarstei at yahoo.com> wrote:
> These are the plugs pulled this morning:
> 
> http://www.superxtune.com/images/plugs.JPG
> 
> I am running LOP (tuned about 16.0:1) at cruise
> engine
> loads and data logs of narrow band O2 sensor show
> 0.000 volts right before the problem starts.
> 
> Hmmm ... how about this scenario, fuel pressure
> drops
> drastically, mixture is too lean to fire
> consistently,
> some unburned mixture left in exhaust and/or chamber
> finally does ignite causing severe backfiring and
> possibly some light detonation.
> 
> Fuel pump/pressure regulator is inside tank but sits
> inches above the front cylinder head... definitely
> could be affected by heat soak.
> 
> 
> Tim



	
		
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