ORIGINAL: MOTORMAN37
I did not run the stock engine. It is now here on rcu. I do not think I lost any RPM since all I did was smooth out the ports, and clean up the crank passage. It could only help. The crank was very rough on the inside passage.
I don't know if it applies to our little engines but when I started working on drag racing V-8's in good ole American muscle cars I was told not to polish the intake runneres as the disruption in airflow helps atomize the fuel for a better burn. I saw your ad for your stock motor and you have it set at a very good price. Let's just say I'm tempted but can't justify it right now.