1994 crossflow 115

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epjman

Cadet
Joined
Sep 16, 2010
Messages
13
Does anyone know the max RPM of the 94 crossflow 115 at WOT? I have an aluminum 13 1/4" x 17 which gives an excellent hole shot but WOT 6000 rpm and 35 mph, a stainless 13 1/4" x 17 cupped sluggish hole shot but WOT 5500 rpm and 40 mph. The motor seems to run smoother with the stainless, probably due to weight.

model - J115JLERC

Eric
 
SparkieBoat

SparkieBoat

Captain
Joined
Aug 17, 2009
Messages
3,643
Re: 1994 crossflow 115

I am not positive the exact range for that specific motor..but i always prop my motors to run 5500-5800 RPMs at WOT unloaded..sounds like your SS prop is the one to use. hole shot should still be good..if you get a set of trim tabs it will improve your hole shot greatly. even the cheap ones work good
 
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yoster

Petty Officer 2nd Class
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Aug 19, 2010
Messages
117
Re: 1994 crossflow 115

My 1997 60-degree 115 has an operating range of 4500-5500 RPM according to the manual. I doubt yours would be higher than that. That said I don't know the 'history' on these engines; someone here might tell you that they could run 6k rpm all day long.
 
SparkieBoat

SparkieBoat

Captain
Joined
Aug 17, 2009
Messages
3,643
Re: 1994 crossflow 115

I know that you can turn Mercs at well over 6K RPMs all day long without hurting the motor, just add some extra oil. But I am pretty sure it is best with OMCs to keep them under 6K..I use 5800 unloaded as my target..then I end up topping out at around 5500 when loaded..just seems to be the best RPM range for all around usage..If I was going to have 2 props I may get it down to 5500 unloaded and then have a ski prop that does 6K unloaded that would be a 2-3 pitch difference in the 2 props..But the SS prop you have should work great for you..keep your aluminum for skiing/tubing
 
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Dhadley

Supreme Mariner
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Feb 4, 2001
Messages
16,978
Re: 1994 crossflow 115

5800 with an average load is your target. Slip-wise you're not too bad with your ss. Not great but not bad.
 
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emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1994 crossflow 115

The factory rated that engine to run between 4500 and 5500 when new. Current thinking is that you should run it in the upper end of the "normal" operating range. As Dhadley says, that engine will make good hp right up to 5800 and I would not have any concerns about running the engine all day long at 5800. You might want to consider moving the engine up one bolt hole on the transom on your boat and then run it with the stainless. You will find a little less drag, the cup on the stainless will give you good bite and you may pick up a few hundred rpm.
 
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