1963 Evinrude Sportwin 9.9 Spun prop hub?

[Chadbud]

Hi!

I bought this 63 Evinrude Sportwin 9.9 on Craigslist last year. It’s very clean and the seller did start it for me at the home.

After having troubles with it staying running and lack of power on the water, I replaced the magneto coils, pins, etc... I also replaced the fuel filter.

Heres my problem: the motor will start in the driveway and idle just fine. When I get it in the water behind a 12’ aluminum John boat it seems to lack almost half its power, then when I sometimes do manage to get it up and going it will lose power stop suddenly while the RPMs skyrocket and then it stalls. Almost like the propeller just got thrown off of it entirely. It sounds like a bad prop hub doesn’t it? Are there even prop hubs on these old motors? I can’t think of what else it could be.


What do you guys think?

 

[racerone]

Yes it does have a rubber drive hub in the prop.----It is a 10 hp and not a 9.9 hp.----When you start it in the driveway you are using cooling water I hope.----It does sound like it is running on one cylinder and then the other kick in.------But there also might be more than one issue too.

 

[merkdawg0084]

Take it to the lake or a barrel, take the hood off and start it. Pull one plug wire at a time and see if it’s a bad coil. Also check the fuel pump, you could be getting fuel when it’s idling, but at high speed the diaphragm could be leaking.