How much more do you want? There are over-bore kits available for that engine to increase CID, then set rpm&#039;s up some, and set fuel up some. 55 pto hp isn&#039;t out of question for long life. Unless you are sure the compression is excellent, I would be very leery of just &amp;quot;cranking up&amp;quot; fuel for power. It is easy to get to much fuel and &amp;quot;wash out&amp;quot; rings, and/or overheat and engine and melt things that can get expensive.  One thing you really never want to see is pistons with holes through them.  Holes in pistons tend to lead to holes in pocketbook.  Which in turn can upset wife, causing further large(r) problems.