Mercury 150 4 stroke rev limit?

[Silverspeed]

I have a 2013 24SL with a Mercury 150 4 stroke.  It is propped with a 15 pitch Vengance prop.  I have seen that the full throttle RPM rev range for this motor is 5000-5800 rpm, but unloaded and unintentinally I have hit 6000-6050 rpm.  So I have 2 questions:

1.  Is there a rev limiter on this motor, and if so, what is it set at?

2.  Any prop suggestions that will keep me from over-revving?

Thanks in advance.

 

[kaydano]

I have a similar boat and motor with a 15p Enertia and my max RPM is 5800.

What hull do you have? What's your top speed?

 

[Silverspeed]

I have a similar boat and motor with a 15p Enertia and my max RPM is 5800.

What hull do you have? What's your top speed?

To be honest, I'd have to look it up.  It a tritoon with strakes but I'm not sure how many different options you can get on the SL.  The center tube is the same size as the outers.  Can you tell me what I have based on that description? lol  And I can't find a single thing on the internet as to if this motor has a rev limiter. 

 

[Silverspeed]

So I just talked to Mercury, and they said the cutoff is 5900 rpm.  So I am guessing that my Tachometer is off, because there was no cuttoff when it read 6000.  

 

[JIm_Andrea]

Just because the ignition cutoff is 5900 doesn't mean the engine stops at 5900....  If it came "unloaded" as you describe it hit 5900 and before the ignition cutoff engaged you are already at 6000+

 

[Silverspeed]

Just because the ignition cutoff is 5900 doesn't mean the engine stops at 5900....  If it came "unloaded" as you describe it hit 5900 and before the ignition cutoff engaged you are already at 6000+

Sorry, I just meant that the boat was unloaded when I hit that RPM, (just me in it).  It will run smooth at an indicated 6000 rpm.  If ignition cuttoff is at 5900, I don't see how this is possible unless my tach is off. 

 

[JIm_Andrea]

ok that makes more sense then.

 

[Bamaman]

If your propeller doesn't ventilate or have any issues, it appears to be propped about right per the rpm's you're pulling.  Most stainless props that go on that motor is a Mercury Enertia prop, however.

 

[Silverspeed]

If your propeller doesn't ventilate or have any issues, it appears to be propped about right per the rpm's you're pulling.  Most stainless props that go on that motor is a Mercury Enertia prop, however.

I does ventilate/blow out when making very sharp turns under moderate throttle with several people on the boat pulling a tube.  Honestly, Ive never had a boat that didn't.  Think a different prop could help this?  Maybe a slight cup on the current prop?

 

[Jack M]

Are you trimming down when making those "very sharp turns " ?

I have an SPS with a 150 Merc. I don't tow ,but still must trim down in a sharp turn .

5800/5900 is my rpm @ wot ."IF" I forget to trim down in a turn it will shoot up to 6200 and ventilate .Then I remember to trim it down .

I run a 15X15 Enertia 

 

[Silverspeed]

Are you trimming down when making those "very sharp turns " ?

I have an SPS with a 150 Merc. I don't tow ,but still must trim down in a sharp turn .

5800/5900 is my rpm @ wot ."IF" I forget to trim down in a turn it will shoot up to 6200 and ventilate .Then I remember to trim it down .

I run a 15X15 Enertia

Always. I have found the boat doesn't like trim at all unless in a straight line. Almost any turn with the trim even slightly up will blow out the prop. I normally just run it with it trimmed all the way down unless I am going a good distance and want to gain a little speed at cruising rpm.

 

[JTaylor]

Jack had to ask about the trimming.  I'm surprised at how many people don't use their trim to optimize how their boat runs.

On Saturday I went out on a friend's boat -- a beautiful Cobalt 262 that he has had for a couple years and uses quite a bit for wakeboarding.  I couldn't believe how much he didn't know about his boat, it's systems, and how to optimize the trim.  I'm all for plug and play, but I do like learning about my toys and how to get the most out of them.