9.9 to 15 hp conversion Johnson Evinrude Part 1
Vložit
- čas přidán 6. 09. 2024
- This is part one of 3 videos I am making about getting the most horsepower out of a 9.9 hp Johnson Evinrude outboard motor. I have more single detailed videos about each step but this is the basic principles of what I did. I plan to have it dyno tested and our goal is 18 hp.
I was told by the service training instructor back when the 9.9 and 15 came out that the 15 already dyno tested out at 18 hp right from the factory.
Boysen "dual stage" reeds give better low end throttle response on the low end but rob top end power. The thick second reed never opens because the first thinner reed open before it; Ok for dirt bikes, lousy for outboards,so this product is simply a gimmick.
If you really want to do a power modification, raise the exhaust ports .065" and champfer them, then, mill .007' off the head to slightly increase compression, and run premium 91 octane fuel. Timing at full throttle can be set to 5 degrees more advance than stock for more top end.
. So the 9.9 is actually a 13hp, and with the 15 carb it jumps up to 18hp, with no other modifications.
you are setting it up as a newer 15hp. That motor stock only made 12-13hp at the prop. they built them to make 15hp at the crankshaft.
I just got a 1978 9.9 I am trying to figure out what carb I have the throat measured 1,3/8 inches
look at the stamp on top of the carb
Nice project.When looking at your pistons a question popped up.On my 20hp Johnson the pistons which are same type as yours the top flat part appear almost have rust colored build up and the others part is black from carbon.What would cause this difference?
I don't know
Tienes una pequeña entraba de agua en la cabeza de ese cilindro. Aplana la culata y ponle empaque nuevo.
Where did you get the tune exhaust from?
A 15 hp motor I got at a scrap yard
ola! precisarei de pecas para meu motor johnson 15 hp.
The casting Marks on the piston makes turbulens haha😅😂😂
is there a way to make a 9.9hp 4 stroke Johnson to a 15hp?
Fred Dumont only 2 stroke
Did you do any porting
Just polished
Hey I have one of these outboard can u help me with the timing
Pura bucha
Embarrassing video dirty mess of a garage no wonder you are out of business
Why are you so obsessed with the cleanliness of my workspace?
How do you blueprint a standard Outboard did you have to balance the crank lol
My 9.9 76 doesn’t need a tuned exhaust does it ? 1 think 74-79 where the same everything but the carb I’m sure the round exhaust and the reeds would give it more top end
My question is did you have to upjet your carb with porting ?
@@jimcatx3090 the tuned exhaust should help no matter what year