New member and some questions

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wineslob

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Aug 28, 2007
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Hi guys and gals. New member here with some questions.

I have a 1961 14' (actually 13'6") Valco alum boat with a 1967 Evinrude 18hp on it. The boat is full sized (most alum boats of that era are as skinny as a canoe), 60" across. I "decked" the boat with 1/2" ply, carpet and added 2 seats, so I added about 100lbs to the roughly 200lb original weight.
Even before I decked it, top speed was/is in about the lower, maybe mid, 20 mph's.
With my wife and daughter (or only 2 of us) in the boat it will just get on plane.
The motor has never sounded like it was getting to full speed @ WOT (book says about 5000?) Prop seems to be correct as it matches the stock reccomended (going from memory 9.5" 3 blade), according to the manual.
Does this sound right? I'd like to get a little more "umfff" out of it, if possible.
I have noticed that the motor came in a 22hp rating also, with the same boreXstroke. I'm not sure if the higher HP was just a carb/intake change or not?

Thanks
Mike
 
HighTrim

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: New member and some questions

First off welcome to iboats! How high is the motor in relation to the transom, adjustable tilt holes? A picture of the stern may help. Does everything seem to be running ok? ALthough mid 20's on that boat doenst seem very far off. Others will be able to verify. Good Luck
 
F

F_R

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Jul 7, 2006
Messages
28,226
Re: New member and some questions

Mid-20s sounds right, if that's anywhere near accurate guess.
 
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rndn

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May 20, 2007
Messages
2,323
Re: New member and some questions

Do you have a GPS or some other way to measure the mid 20's or is it a rough guess? If a guess maybe you can ask someone with a handheld GPS to let you use it to get an accurate speed and then you also need to measure the RPM's. Marina's have a tach they can run on your outboard to give you the rpm's instead of just guessing. It should not cost much if anything as my marina checked mine for free.
 
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wineslob

Recruit
Joined
Aug 28, 2007
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5
Re: New member and some questions

Thanks for the responses. The mph is a rough guess. I dont really have a marina near by to check the mph. I've had other people in the boat who pretty much said thay thought it was going a little slow. They also said it dident sound like it was revving up all the way (same as me). One other thing, unlike other boats of the same size/hp you have to keep it wot, no getting on plane and then backing off a little. Kinda all or slower. Guess I'm spolied by my buddies 89' 20 hp Merc that hauls a**. (it walks away from me like I'm standing still) :p
 
iwombat

iwombat

Captain
Joined
Jul 12, 2006
Messages
3,767
Re: New member and some questions

I'd suggest spending $50 or so on a tiny tach and using that to set up the motor on the boat correctly. Fiddle with height and trim until you get the highest rpms. You can then see if maybe a different prop is in order, or there's something not quite right with your motor.
 
jtexas

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: New member and some questions

Compression results would help evaluate whether she's capable of more.
 
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wineslob

Recruit
Joined
Aug 28, 2007
Messages
5
Re: New member and some questions

I checked it last year (comp) it was about 130lb both cyl.
 
samo_ott

samo_ott

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Jun 18, 2006
Messages
5,125
Re: New member and some questions

I have a '61 18hp on my 14' aluminum boat and with 2 big guys in it (~230lbs each) it's pretty quick. No problem to plane. But I have never taken my gps out in it so do not know the speed and the boat is empty and light.
 
D

dajohnson53

Lieutenant Commander
Joined
Apr 28, 2004
Messages
1,627
Re: New member and some questions

wineslob said:
Thanks for the responses. The mph is a rough guess. I dont really have a marina near by to check the mph. I've had other people in the boat who pretty much said thay thought it was going a little slow. They also said it dident sound like it was revving up all the way (same as me). One other thing, unlike other boats of the same size/hp you have to keep it wot, no getting on plane and then backing off a little. Kinda all or slower. Guess I'm spolied by my buddies 89' 20 hp Merc that hauls a**. (it walks away from me like I'm standing still) :p
Click to expand...

Couple of things come to my mind. Like others have said, you really need some objective info to determine if your set up is correct - rpm at WOT for prop and also, check to see if the anti ventilation plate on the motor (just above the pop) is within an inch or two of the bottom of the boat.

Also, trim (the way the boat sits in the water when underway) can make a big difference. You can adjust the trim of the motor to get the nose up or down.

RE: your friend's rig - your friend's modern 20 hp is probably a lot more powerful than your 60's 18 hp. Foremost, your motor rated HP at the powerhead, his is rated at the prop. I don't know the % difference in the two methods, but your 18 carries a lot fewer HP to the prop than his - I'm thinking probably it might be like a 15 prop rated engine at most.

Plus his boat hull might be totally different than yours in weight and shape.
 
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buckstop108

Seaman
Joined
Aug 2, 2007
Messages
67
Re: New member and some questions

You stated you added some wood decks and carpet. With that is there a trolling motor up front with some batteries? any added weight up front will effect your hole shot. You may want to look into a four bladed prop to improve the hole shot with the extra weight.
 
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wineslob

Recruit
Joined
Aug 28, 2007
Messages
5
Re: New member and some questions

No trolling motor up front. (not a Bass Boat) I'm guessing I added 150lb to the boat, but thats just a guess. I rebuilt the carb on it, and replaced the fuel pump. I'll see how she runs the next time I take her out.
 
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