9.9 performance

[stratos201s]

How do yall feel about upgrading the 9.9's? I have a 1978 9.9 that I would like to get a little more out of. Obviously I got it cuz it is legal on natural lakes but now I'm wanting a little more. Don't really feel like buying a new larger motor cuz of the weight and then also I'm running a 12 x 32 jon boat. Handles great currently and love how easy it is to load/unload just want a little more....like 15 to 20 hp at the prop. That's a stretch i'm sure but I'll keep hoping. I know the 15's had interchangeable parts for 9.9s but which ones? Mine is a 10r78m model johnson. Thanks for the recommendations!

 

[Rick.]

Re: 9.9 performance

This topic has been much talked about over the years. If you do a search you'll find lots of threads pertaining to converting a 9.9 to a 15. Never a 20 I don't think. My personal opinion is buy a 15 and put the 9.9 cowl on it if you desire a 15. Best of luck. Rick.

 

[JB]

Re: 9.9 performance

I tend to favor optimizing the rigging, prop, etc. There is usually a lot of improvement available there without harming a perfectly good outboard.

 

[Will Bark]

Re: 9.9 performance

It is said that a 9.9 is nothing more than a 15 "choked" down to the 9.9 so you could get on 10hp lakes which was popular back in the 70's and 80's. The 9.9 has a carb with a smaller throat than the 15 and changing carbs; not just the jets will increase the hp. If scanman is reading this he would be able to tell you exactly what he got out of his 9.9 when he changed to a 15hp carb or you could PM scanman and ask him. Good luck