Yeah I definately understand your skepticism. I have been a longtime lurker but have been on many other forums for years. I spent alot of time looking for these and wanted to share the knowledge. I have not validated every link on this site. The 9.9 manual was the one that most concered me and it was fine. As with any online downloads one should always filter them through an Antivirus software. Personally I use AVG Free and love it
Well I just downloaded the manual for my brothers 20hp merc 2 stroke and it is an awesome manual!!!
I was curious as to how the 20hp and 25hp motors were different and if you look around the manual a little bit you can find some differences in the carb and jets. I am still planning on reading up and researching the motor further but it looks like a relatively simple upgrade to make the 20 a 25. The main jet on the 20 is .44 and the main jet on the 25 is .76. Oh and the main jet on the 25 commercial is .80. There are no other significant differences in the entire carb and all the other specs are the exact same.
Looks like we are headed to to Outboard Shop in Pompano to order up a few jets... Gotta go there anyways for a carb rebuild kit. Will report back with results. Ahhh the never ending search for more HP... Don't ya just love America!!!