Breadman- Here are some things you also need to check for that lean condition

1 airbox thermostat, if it is defective you may be sucking hot air from the pre-heater hose

2 pull off plastic hose between the AMM and the manifold, hold it up to the light and check it for small holes. They sometimes rub against the body or other hoses and develope leaks.

3 I have not tried the method you refer to for the combustion chambers, in the old days they called that The Chinese Water Torture. The method I use is to run a bottle of combustion chamber cleaner in the tank and when the tank is almost done I give it the old Italian Tune-Up, (low gear 4500 rpm for 45-60 sec.)

These three things have worked wonders for me.

GOOD LUCK,
--
Bruce S. near D.C.