Too slow?

[wsr3]

Hi,
I have a 1963 Glasspar Marathon 14ft. appx 460lbs. with a 1971 Evinrude 60 appx 225lbs.. With three people, twelve gallons of fuel and maybe 50 lb of gear I'm only managing about 25 mph at 4750 rpm wot. I'm running a 13 1/4 x 17 three blade aluminum which is the stock prop for this motor and it is in good shape. I recently had the carbs serviced. Is this reasonable or should I be looking for motor problems?
Thanks,
Bill

 

[Aqualift]

Re: Too slow?

That's about right. With all the weight (1300lbs+/-), you might want to go down in prop pitch to bump up your RPM's some.

 

[Bob_VT]

Re: Too slow?

You are shy on the OT....... being a 1963 boat you might have water in the hull or in the foam...... Have you checked?

 

[26aftcab454]

Re: Too slow?

back in 1963 would would be haulin AZZ!

 

[Chris1956]

Re: Too slow?

Bill, something is amiss. That boat should hit 30MPH+, with that power. The boat is probably over max HP.

Check the weight of the boat, and drop the prop pitch 4" and see what she will do.

 

[steelespike]

Re: Too slow?

Be sure the motor is as high as it can go without venting(cavitation) problems.
Typically the antivent plate ends up about an inch higher than the bottom of the boat.This can gain a couple of mph or more.
Be sure the throttle opens all the way.Motor in excellent tune,prop in excellent condition.Bottom of boat clean with no deformities.
A small boat may struggle more with a load than a boat with a larger bottom surface area.As suggested it may have absorbed some water over the years.

 

[wsr3]

Re: Too slow?

I did think that the motor was too low and raised it, I haven't had it back in the water yet though. From what I have been able to find the boat is rated 40-75 hp, of course these were 1963 hp. When I was changing the water pump I found that seal between the exhaust camber and the foot was mis installed and corrected it, but again, haven't had it back out. How would I go about checking for water in the hull? I don't think that it has floatation, but I'm not sure.
Thanks,
Bill