1994 mercury 115 rpm

luckytempo93

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Apr 20, 2008
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14
what are the opperating rpm's of this engine. i want to run a 4 blade and need to know what the max is. and should i run the 4 blade near the max for the most speed. or will i save the engine some life if in the lower range. thanks
 

j_martin

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Sep 22, 2006
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7,474
Re: 1994 mercury 115 rpm

It's easier on them to over rev a bit than to lug.

John
 

luckytempo93

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Apr 20, 2008
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Re: 1994 mercury 115 rpm

right now i have a 12 3/4 X 21p prop on and i think im running around 5900rpm. i do know that is really high. and thats by myself. so if i go with a 4 blade should that bring it down to where it would best perform or should i go up an inch in pitch and do a 4 blade. i have a 1994 nitro bass boat and it does 48mph with a gps on the blade above. and i want to try the 4 blade cause i want to get out of the hole faster.
 

j_martin

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Sep 22, 2006
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7,474
Re: 1994 mercury 115 rpm

Raising the pitch is going to hurt your hole shot. Where does it run with the live wells full and a 200 lb fishing partner in it? If the numbers you posted are alone and dry, you're about set up for fishing now.

What is your hole shot like. Does it overload the motor, or does the prop slip and not grab good?

I run a high five, which bites in real good, but it's ventilated enough so the XR4 that drives it can spool up to almost 3 grand before it bites. It's a neck snapper.

Engine mounting, and handling the trim can have huge effects on hole shot also.

hope it helps
John
 

luckytempo93

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Apr 20, 2008
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Re: 1994 mercury 115 rpm

i will try to find out what it is like with all my tackle and another person in the boat with me. right now my 3 blade is good. im looking for a new one cause i have nicked it up last year a bit. and the merc dealier said i need a 23pitch prop. so im in the market. i had a comprop on and it was a 4 blade. wow did that get me out of the water fast but i think it was cracked and i lost a blade and made me think it was my motor. but i liked how it just poped up and went...
 

j_martin

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Sep 22, 2006
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7,474
Re: 1994 mercury 115 rpm

Most of the 4 and 5 blade props have such a hard bite that they are ventilated, so some exhaust gets into the prop stream and lets the prop slip. When your speed is up, no exhaust goes out the vent and the prop bites as if it wasn't vented.

Effect is like slipping the clutch at a drag race. It lets the engine spool up and make horses, then hooks in.

I think you'd like the high five.

John
 

pops

Petty Officer 3rd Class
Joined
Jul 8, 2007
Messages
76
Re: 1994 mercury 115 rpm

LT, I have a '95 115 Mariner (same motor, different color) on a Ranger Sport 70 (17') Bass boat. The rig came from the factory with a Merc. Quicksilver Laser II that is 13 1/2 X 22P.

The prop allows the motor to run at approx. 5100 rpm, trimmed up at normal fishing weight and water in the live well. This is around 50 mph on GPS.

The prop gives a good hole shot and I have been well satisfied with the overall performance.

I would be afraid to turn a 115 to the rpms you are seeing presently. Can you spell GRENADE!
 

luckytempo93

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Joined
Apr 20, 2008
Messages
14
Re: 1994 mercury 115 rpm

haha ya... KAAA-BOOMMMM (recussion form echo) 2000... 2000...... dollars...... well the boat is seeing water tomorrow and i will see what the rpm range is. thanks and i will keep you posted on what i find
 
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