before we get too far off topic, could the blowback into the Air Tube be caused by a clogged or performing-not-to-spec PVC valve?

I just ordered one from my local O'Reilys Autoparts which won't be here till Tuesday.

I noticed that there is not "How-To" listed on changing a PVC valve. If the forum likes, I can take pics of the process and post them...that is, if this process involves taking parts of the intake off to gain access. Otherwise it's way too straight forward.

And, while I'd like to put in a big fat engine, I need the gas milage of the little engine that should. :)