Too lean,or not Too lean,that is the question

[RMartin]

I've read alot of posts on this board about reading spark plugs and have a question. I've got an old Clymer manual with some pics of spark plugs and what they should and shouldn't look like. After finally getting my car running good, I decided to put new plugs in last weekend. I wanted to try some plugs that Early S Man recommended. The plugs I took out were really clean, with a grey or light tan color, just like the pic in my manual. But I suspect that some people on this board might say it looked like my engine is running too lean.
So, my question is how do you correct a too lean engine? With a carb adjustment? I really hate to mess with the carbs now. Are there other signs of an engine that is running too lean besides reading spark plugs or a hole in a piston?

BTW, My engine is a 2.0 S with stock carbs.

[TimT]

Interesting reading about the lean myth

Im sure other will jump all over this stating its comparing apples and oranges.. whatever

when the engine is operating in a static state (say cruising at 55, 65, or 70) this makes sense...

enjoy!!

BTW changing main jets is a breeze with weber carbs..

[jluetjen]

Does it ping or detonate? Is there lean surge (when you ease off the throttle the car actually picks up speed briefly)?

If it runs fine and you have none of the above problems, I'd argue that chances are you are not too lean.

[Tyson Schmidt]

Don't try to read plugs with unleaded gas. That's just not a good way to do it anymore. Todays fuels burn so clean, that the right mixture will give the plug a very lean look.

[aigel]

Just get the a/f meter from innovate. pelican sells it. Then measure your a/f ratio at the tail pipe and dial it in perfectly. Tyson is correct, today's fuels make it very hard to read plugs.

G

[RMartin]

Good advice guys, thanks

[beepbeep]

Originally posted by jluetjen
Does it ping or detonate? Is there lean surge (when you ease off the throttle the car actually picks up speed briefly)?

If it runs fine and you have none of the above problems, I'd argue that chances are you are not too lean.

These are good hints. Car running too lean will "surge" when you let off the throttle. It will missfire sometimes at full throttle and it will detonate at high load /low RPM (it will actually detonate at high RPM as well, but you won't hear it before it's too late).

Reading plugs is hard, unless you runt it at full load and then suddenly shut off the engine, coast to stop and pull the plugs.