Am I Crazy?

[Solomon Shaffer]

Here are the specs on my boat, then I'll tell you the problem.

I have a 1967, 15' Renken Runabout with a 1981 Mercury 50hp.

I've cleaned the carbs and got it running pretty well, but there is
an issue that's bugging me. I need you to tell me if I'm crazy or if
it's ok.

I had four people in the boat, 11 gallons of gas, a battery and other gear.
When I go to accelerate to WOT, it seems to open up veryslowly. If I drop the throttle to full, it takes forever to get on plane, then it will finally open up and scream (though I think it's not running at its fullest RPMS...no tach to tell)

Am I crazy or should that engine pretty much scream a few seconds after I open it up? It's just a propeller in water...isn't it much different than a car on pavement? Shouldn't the engine get most of it's RPMS even if the boat was tied to the dock?

Does this have anything to do with trim? I ran it in the next to the lowest position today...Any ideas would be appreciated...I know it's only a 50hp, but I think it should be accelerating faster.

 

[JB]

Re: Am I Crazy?

Put a tach on it and test for proper prop.

 

[j_martin]

Re: Am I Crazy?

The hot rods that spool up to about 3000 rpm, then bite usually are running a ventilated prop. The vents let exhaust gas spoil the traction till the forward motion pulls the exhaust stream back into the barrel.

Works good. Mine is a high five.

 

[Solomon Shaffer]

Re: Am I Crazy?

J Martin,
So you are saying that the prop is spooling (slipping) and then grabbing due to the exhaust? How can I fix this?

If that is true, wouldn't the engine rev higher and then go under a load as the prop grabbed?