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Ok I picked up a 71 marlin ski boat v bottom with an 85hp v4 Johnson and 3 blade aluminum prop. I bought this boat to just bomb around in. I got it home and replace the stringer and the floor and put in a bulkhead. I thought before I paint it I should take it out and try it to see if its ill handling ect.
Well here is what i found. Its not fast at all. Im looking to go about 50 to 55mph is this possible? The guy before me said it goes 45.. Well I would say he is full of crap. My guess is 32mph at best... What are your thoughts?
The engine has power tilt. I couldnt even get going fast enough to blow my hat off.
What do I have to do to get it to go 55mph? :D
 

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Ok I picked up a 71 marlin ski boat v bottom with an 85hp v4 Johnson and 3 blade aluminum prop. I bought this boat to just bomb around in. I got it home and replace the stringer and the floor and put in a bulkhead. I thought before I paint it I should take it out and try it to see if its ill handling ect.
Well here is what i found. Its not fast at all. Im looking to go about 50 to 55mph is this possible? The guy before me said it goes 45.. Well I would say he is full of crap. My guess is 32mph at best... What are your thoughts?
The engine has power tilt. I couldnt even get going fast enough to blow my hat off.
What do I have to do to get it to go 55mph? :D
I'd say you have a pretty typical outboard.

They make great fishing and day trip boats but if you're looking for cool factor it aint gonna happen. :)hand
 

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Im not even sure this would pull me up on a skis LMAO Feels like a moped on water after driving a crotch rocket
 

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Ok I picked up a 71 marlin ski boat v bottom with an 85hp v4 Johnson and 3 blade aluminum prop. I bought this boat to just bomb around in. I got it home and replace the stringer and the floor and put in a bulkhead. I thought before I paint it I should take it out and try it to see if its ill handling ect.
Well here is what i found. Its not fast at all. Im looking to go about 50 to 55mph is this possible? The guy before me said it goes 45.. Well I would say he is full of crap. My guess is 32mph at best... What are your thoughts?
The engine has power tilt. I couldnt even get going fast enough to blow my hat off.
What do I have to do to get it to go 55mph? :D
Put a 300 on the back of it, Flywheel it and a nosecone. $15,000 later you'll have a 65 mph pile of shit......:D
 

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Back in the day... 1975 to be exact, I bought my first new boat! A Sea Star tri-hull 15 footer with a V-4 Evenrude O.B. As delivered, the top speed with the 19" 3 blade aluminum prop was 34 mph. By the end of summer, after the following mods, top speed hit 48-49 on a good day with just me in it, and 2 peeps reliably 44-45mph. Raised motor one set of holes up on the transom. Added a 21" SS cupped performance prop. Added 3/8" spacers on the air cleaner plate under the carbs(allows more air into the cowl). Bought a set of 115 HP carb jets, and they were a bit rich, so I took the stock jets to a machineshop and had them ream the stock ones out to half way between them and the 115 jets. MUCH BETTER! Played with timing (added 2 degrees at a time and ran it for an hour and read the plugs. As I remember, I was up on the timing about 3-4 degrees from stock. PUT THE BIGGER JETS IN IT FIRST!!!!! Spaced out the (sound)baffle plate in front of the carb inlets about 1/4" or slightly more. Side gapped the spark plugs and increased the gap by .005". Indexed the plug gaps (Moroso copper index washers)to put the gap perpendicular to the crossflow of mixture. Ported (bigger and radiused) the exhaust opening around the prop shaft, and opened up the exhaust hole slots in the props also with a die grinder. If you don't mind running premium fuel, have the heads milled by .025-.030, or have a set of solid copper headgaskets waterjet cut using the stock ones for a pattern only .020/.025 thinner. I think the stock headgaskets were about .050 thick. Use copper coat upon reinstallation. Aftermarket reeds may help the top end very slightly, unless your stockers are trashed. Mostly they only seem to help midrange acceleration, slightly. The 115, and 135 motors are the same engine with a few more cubic inches, and not that many more. Mostly the compression ratio, carb size and porting are the major differences. Lather, rinse, repeat, enjoy. TIMINATOR
 

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P.S. the flywheel will do nothing for the top end, only transient response, and the nosecone won't help under about 70 MPH. Been there, done that too. I only mentioned what I know has worked, and on a bunch of motors. After Friday nite testing I will post the latest hop-up O.B. project. A 2 cylinder 40 HP Nissan. TIMINATOR
 

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More power. I have a mildly modded 150 Merc up for grabs, you can see it run if your gonna be at Hardy this weekend.
 

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Under yo mommas bed
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Ok I picked up a 71 marlin ski boat v bottom with an 85hp v4 Johnson and 3 blade aluminum prop. I bought this boat to just bomb around in. I got it home and replace the stringer and the floor and put in a bulkhead. I thought before I paint it I should take it out and try it to see if its ill handling ect.
Well here is what i found. Its not fast at all. Im looking to go about 50 to 55mph is this possible? The guy before me said it goes 45.. Well I would say he is full of crap. My guess is 32mph at best... What are your thoughts?
The engine has power tilt. I couldnt even get going fast enough to blow my hat off.
What do I have to do to get it to go 55mph? :D
I think you need to start over. Get a hull with a pad and try a larger motor. You could put a pad on it but it's a lot of work. JM.02:)hand
 

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i would think about getting a newer (not necessarily brand new) 150 or larger motor. Put a jack-plate on it and trim tabs if you dont have em and be done. Agree with the above post and getting a gps reading first
 

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Ok I picked up a 71 marlin ski boat v bottom with an 85hp v4 Johnson and 3 blade aluminum prop. I bought this boat to just bomb around in. I got it home and replace the stringer and the floor and put in a bulkhead. I thought before I paint it I should take it out and try it to see if its ill handling ect.
Well here is what i found. Its not fast at all. Im looking to go about 50 to 55mph is this possible? The guy before me said it goes 45.. Well I would say he is full of crap. My guess is 32mph at best... What are your thoughts?
The engine has power tilt. I couldnt even get going fast enough to blow my hat off.
What do I have to do to get it to go 55mph? :D

If it wont run faster than it will sink ..............................PULL THE PLUG :D
 

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Discussion Starter #17
Trust me Sleek I wont get caught dead running this boat anywhere my hot rod boat friends hang out this thing is a moped on water lol
 

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What does the boat look like? can post some pic's.

what lenght is it?

What is the hull design? Does the V have a pad?

What prop are you running?

What height is the cavitation plate, relative to the bottom of the boat? (x dimension, is that, or prop shaft)

I've had many outboards, and the trick is, lift it as heigh as you can, if you don't cavitate when getting on plane, its too low!!

No rooster tail, it's to low.

No water pressure, too high!

Cavitation @ speed, too high

A power transom is the answer, but why waste the money, if the hull won't work.
 
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