Merc 3.7L, 165hp, Power Expectation

ta400man

Seaman Apprentice
Joined
Mar 22, 2006
Messages
46
Hello All; I have a Sunbird 1987, 18ft Eurosport I, merc 3.7L, 1987, 165hp, 4cyc. with the alpha one drive. <br /><br />The boat weights 2300lbs, I wondering what kind of performance I should expect. Assuming the engine is running in top condition.<br /><br />Will it have a hard time pulling a skiier up, with 5 people on the boat. The boat is rated for 6 people @ 900lbs with 120lba of gear.<br /><br />I hope it will not, but I will find out in a few weeks when I beem it ready for the water.<br /><br />What kinds of speeds should I expect?<br /><br />Thanks In Advance,<br />Shawn
 

whywhyzed

Banned
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Feb 1, 2005
Messages
1,871
Re: Merc 3.7L, 165hp, Power Expectation

speed I would estimate 38 mph with the 6 people, 44 with one or two people.<br />Skiing will be "ok" , nothing special with all that weight. An experienced skiier will be able to get up ok I think.
 

ta400man

Seaman Apprentice
Joined
Mar 22, 2006
Messages
46
Re: Merc 3.7L, 165hp, Power Expectation

Thanks for the information.
 

Almeja

Seaman
Joined
May 30, 2006
Messages
70
Re: Merc 3.7L, 165hp, Power Expectation

What pitch prop is on it?<br /><br />You may want to down-pitch for skiing or pulling water toys. (that's what I'm doing this year)
 

ta400man

Seaman Apprentice
Joined
Mar 22, 2006
Messages
46
Re: Merc 3.7L, 165hp, Power Expectation

The pitch is something I still need to investiage. I forgot to look into that, thanks for reminding me.
 

MrBill

Senior Chief Petty Officer
Joined
Aug 4, 2002
Messages
710
Re: Merc 3.7L, 165hp, Power Expectation

I have the 3.7L 165HP in a 19 ft 2600lb boat rated 10 persons/1200lbs and have no trouble pulling up a 200 lb slalom skier. The engine is known to be a torque monster, top-end on mine with five aboard is about 36-38 mph with a 19 pitch prop. I use the 19 inch prop for getting skiers out of the water and pulling 2 tubers or knee-boarders. With the 19" I could over-rev the recommended 4400 to 4600 redline. To prohibit over revving, I'd need to go with a 21 pitch prop, and top-end would go to about 45 mph.
 

ta400man

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Joined
Mar 22, 2006
Messages
46
Re: Merc 3.7L, 165hp, Power Expectation

I checked the number on the prop and I found the number 48-78118-A40???. So I googled the number 48-78118 and found out the prop has a pitch of 17. I figured that this is a really low pitch for the boat. <br /><br />I figured that the out drive gear ratio is 1.84, and WOT is 4800rpm , assuming a 15% prop slippage. I would only be going about 35 max speed. This is enough speed for skiing?
 

MrBill

Senior Chief Petty Officer
Joined
Aug 4, 2002
Messages
710
Re: Merc 3.7L, 165hp, Power Expectation

Yes...35 mph is plenty for skiing, unless you're bare footing.
 
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