Different carb. By the way, what is your compression. While going to a
larger carb and rejetting, you might want to consider upping the compression
to say 140 psi by having the head shaved. This will really make a
difference on acceleration and you can advance the timing since you will be
running 93 octane fuel. Just make sure you get a tach of some kind to hook
up so you don't overrev the engine or you know what prop to change to.

--
Tony
My boats and autos - http://t.thomas.home.mchsi.com



"us104" wrote in message
...
Thanx for help!
The engineblock and cc is the same so it must be as you say.
Do you if it is possible to work with the carb or if its easier to get
hold
of a 30hp carb?
matts


"Tony Thomas" wrote in message
news:0QH9b.475528$Ho3.80058@sccrnsc03...
Not sure on that year. I know the carbs are different. The exhaust
tuner
may be different along w/ the ports.
Start w/ the carb and go from there. Should get you some power anyway.

--
Tony
My boats and autos - http://t.thomas.home.mchsi.com



"swedishconnection" wrote in message
...
Anyone knows anything about tuning a Johnson 20hp,1990,Two-stroke to
30hp??
I do gladly accept any advice on that!
matts


"swedishconnection" wrote in message
...
I have a Johnson 20hp,1990,Two-stroke.Just run 60 hours.
To pull waterskies with my Zodiac I need 10 more hp.
Does anyone know how complicated it is to "scare" the motor to 30
hp?
How is it done?
Grateful for any tip!
matts