Boy...you guys that do not know Pe R. and what his background is, you better go back and read everything you can find about Hopping up a Ryobi engine. There has been many other Real good posts & threads hopping up this engine. I can tell you have not even scratched the surface on what can be done with this engine and many other engines. I suggest get some reading done before you Tell us a Guys tack must be off. Sounds like you tack my be off and that is not all thats may be off!!! Lord...have Mercy! Also do not expect me to look up any data on this engine. I will not baby set anyone not willing to take the time to dig up data ...do it youself! Capt,n