oldjag wrote:
CO is combustible in air, but has a pretty high auto igntion
temperature. Typical exhaust CO level from a gasoline engine is that
is operating at a stoichometric air fuel ratio is around 0.5 to 1%.
Stoic. on a gasoline engine is about 14.7:1 air to fuel ratio on a mass
basis. CO goes concentration goes up very quickly if the engine is
running rich of stoic. or has poor cylinder to cylinder fuel
distribution, or a missfire. An engine will run quite nicely at 5% CO.
Unfortunatly, if the engine fuel distribution is bad or the engine is
missfiring, the O2 concentration in the exhaust will also go up. If a
gasoline engine is running at stoic, and has good fuel distribution,
the exhaust could be fairly "inert", but this cannot be counted on
unless it is being monitored with a gas analyzer. With after
treatment, ie. a functioning catalyst and running at stoic., CO and HC
exhaust concentrations can be in the PPM range.

My new-to-me 2002 Aprilia RS50 scootah idles at about 50:1 air:fuel and
has a lovely muffler power band and mellow tone. I've hit 55 on it.
From a 50!

Looking forward to dropping in a 70 kit, gas porting the rings, and
riding the Blue Ridge.

It's got the Ditech system. Direct Injection Technology. Kinda like a
diesel injector, but it's actually a rich mixture of air and fuel being
injected. Scavenged by clean air and I think an oil spray. There's no
conventional carb. (I haven't got a manual yet. There's not much you
can do to one of these. It's all regulated by a silicon chip.)

Anyhoo, it was the bang-for-buck cleanest thing I could get in my price
range. After we sell the condo, I'm going to go for a hybrid and start
playing with ultracapacitors again.

For more on that; see "Happy New Year".

Doug Goncz
Replikon Research
Falls Church, VA 22044-0394