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Author Topic:   Prop suggestion
JayR posted 12-31-2003 10:12 PM ET (US)   Profile for JayR   Send Email to JayR  
I am going to put an Evinrude 88SPL on my newly acquired 1971 21' 4" Outrage.

Now before you jump and scream about how under powered it will be, hear me out....

I am not certain I will keep the boat as I also have 1988 20' Guardian and a 1967 Madetauk.

The real question is whether or not I will like the boat well enough to put a new motor on it and keep it. I use my boats in a peculiar manner. I launch and retrieve them on the sand beaches of Cape Cod without the aid of a trailer. The boat being very light a fairly flat bottomed in the aft section has a huge advantage over the Guardian. However, the ride quality concerns me.

I wish to give the boat a try out for ride and for its' fishing comfort before investing into a new motor.

The previous owner had a 90 HP honda on it and said he could get over 30 knots with it. That would be plenty for my trials.

The question is... the motor presently has an aluminum 13 1/4 x 17. Would this suffice or should I plan on another propeller?

Your advice on the prop would be greatly appreciated.

Sal DiMercurio posted 01-01-2004 02:40 AM ET (US)     Profile for Sal DiMercurio  Send Email to Sal DiMercurio     
I believe that 88 sp is rated at 5,500 max, so you need to run that rig with the 13.25 x 17 prop & see just how many rpms she can twist.
If she turns 5,500 rpms, your fine, if she only gets 5,000 rpms, your gonna have to go with a 13.25 x 15 pitch to allow that engine to spin up to 5,400 rpms which is close enough.
Be sure you set the back of the tach to #6 because all OMC engines are #6 & if it's not set correctly, it will give a false reading.
Off the top of my head, i'll say a 13.25 x 15 might do it.
Be sure you mount that engine up at least on the 3rd set of holes to start with, that should give you a few hundred more rpms then all the way down.
If she blows out in a tight turn or rough water, drop her down a set of holes.
You might want to concider a s/s Stiletto to lift the hull more then the aluminum omc prop which wont lift near as much.
The Stiletto could bring the rpms down [ less slip ] , but if the engine is mounted high enough, the height should give those rpms back.
Come back here & let us know your current rpms with the stock aluminum prop & we'll adjust from there.
Very immportant to mount the engine high enough, not right down on the transom.
Sal
Clark Roberts posted 01-01-2004 08:01 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
Jay, I ran a 1995/6 Merc 90 on my 21'4" 1979 Revenge for about 3 years and it was an amazing combination. It would run 35mph at full throttle with light load and cruise at 22-25 mph at 4400 (as I recall) all day long and get over 3 mpg in the process. The draft was minimum due to the relatively light weight (304lbs) and handling was quick and precise. I am now running a 115 EFI four stroker and it is a little faster and gets about 5.5mpg but that 90 was a great motor for that hull if speed is not a major concern. I also have a 21'4" 1975 Outrage with a 200 EFI (55+ mph) so I'm not the complete slow poke that I might appear. Once you get the right prop (per above great advice) you might love that 88hp (more displacement/torque than my 90hp) and decide to keep it. As to handling, it will amaze you; as to ride in chop, it will beat you silly at times (but, trust me, all hulls will at some speed in some conditions); the ease of access from docks and water will be so convient; as to visibility from helm, perfect; as to shallow water capabilities; put a jack plate on it and it will bo anywhere a Montauk will go.... etc, etc, etc... Can you tell that I love this hull? I had a stranger ask me recently if my Revenge was some new Whaler model. Of course he new little of Whalers and was shocked when I told him it was 25 years old. I don't know how many of these hulls were made but if you have one my advice would be to keep it as there will never be any more. Blah, blah, blah... Clark .. Spruce Creek Navy
JayR posted 01-01-2004 08:37 AM ET (US)     Profile for JayR  Send Email to JayR     
Sal & Clark,

Thank you... The 88SPL is coming off my Madetauk for the trial. It already has a 13.25 x 17 prop on it and on the Madetauk it spins at 5500-5700 if pushed so maybe the 15 would be better. In any case, I will give it a go as soon as the weather will permit.

The 88SPL is a 1988 model and I was hoping to sell it on the Madetauk in the event I keep the Outrage. After that report, I am concerned it will run all to well and the wife will suggest that I not get that new Suzuki 140 4 stroke. Hmmmmmm....

I guess only time will tell.

JayR posted 01-03-2004 07:08 AM ET (US)     Profile for JayR  Send Email to JayR     
So much for the trila run... Wife saw this thread and informed me that "her" boat was getting a new Suzuki 140 4 Stroke before spring. :-;

I guess I could have heard worse things...

So what do I do with the 20' Guardian?

JayR posted 01-03-2004 07:09 AM ET (US)     Profile for JayR  Send Email to JayR     
"trial" duh!

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