I own a super 44a (The big brother to the d44) and have had the chance to run a d44 in good tune. The d44 ran about like a 1-53 or 250mac, that is to say very torquey and medium rpm's. These saws always benifit from big sprockets a switch to 3/8 chain and sprocket tip bars. Check ebay and see what those reed valve 80cc macs are going for if you want to know what they will bring. If you get a chance to snag a s44a grab it cuz it is a different beast altogether. It's not just the 7 extra cc's but also the porting is way more aggressive as this was a cart engine. They were rated at 6.5 hp but will definately suprise you. Also they rev better than you would think.