Top speed with 18hp Evinrude on 14′ aluminum

[Mumbles]

If the top one is bad, it might be time to start thinking about the bottom one. Especially if they are both the same age and original.

In your video, are you turning the motor over by the prop?

Remove the plugs, reinstall the flywheel nut and use a socket on the nut. You will have much more control over the speed. 😀

[stephenspann27]

I replaced the bottom carbon seal when I installed this power head so it should be fine. I was turning the prop with my foot, while the plugs where out.

[stephenspann27]

I replaced the top crank seal today and tested the motor. No change, other than I had to re-adjust the idle speed now that the air leak at the seal is gone. With two new spark plugs I got the same results as before. The top plug looks like it’s never been touched by fuel, and the bottom plug is dark and sooted. With a single carb motor, with great spark on each cylinder I"m trying to think what could cause this. When I run the motor in a barrel I get a ton of milkey oil in the barrell. I also have some oil soot leaking at the powerhead/mid section gasket. The gaskets are new and the bolts are tight. I"m wondering if water is getting in at the base gasket maybe..

[stephenspann27]

Something else I’ll add. I was thinking I’m not getting over 3,500 RPM because it’s having trouble pushing the heavy load with probably only one cylinder working. Today I went full throttle in reverse, which doesn’t put much load on the motor at all, and it still didn’t go over 3,500rpm.

[Mumbles]

Without reading this whole topic again, are you sure the carb is opening fully and the timing is going to full advance?

Take a look at the shift lock lever and the brass plate on the mag plate when you advance the throttle with the motor in gear and in neutral. There are steps on the brass plate and the lock lever contacts these to limit the motor speed depending on which position the shift lever is in. One step limits neutral speed and another might limit it while in reverse. In forward gear there will be no contact and this allows full throttle operation.

Here’s a ’56 mag plate but yours should be similar.

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[stephenspann27]

The carb butterfly is opening all the way and the timing advance goes to the max. I don’t think my motors has any kind of shift lock stuff? I can start it in gear, and I can go wide open in neutral. I’ll double check.

[stephenspann27]

I bet this piece is supposed to be taller isn’t it?

[stephenspann27]

Here are the positions at WOT

[david-bartlett]

quote stephenspann27:

I bet this piece is supposed to be taller isn’t it?

Yes it is, that one has been cut off. Nothing to stop you from going to WOT regardless of whether it is in gear or not.

You don’t have a reed problem? Stuck really bad on one side?

[stephenspann27]

maybe I do, I haven’t had the manifold off on this motor yet.

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