Rev limiter Verado 400R

[ToffenG]

Hey,

I am spinning 7060 rpms at 89 mph with my Verado 400R on my Phantom 25. I run a Max5 25 pitch prop. I have been told I am hitting the soft rev limiter. Anyone know if this is correct?

Thanks!

Cheeers, Toffen

[davidwademarine]

Max RPM on the 400R is 7000. It can be spun a little higher as you’ve noticed, but will get the overspeed alarm. I’m not sure if the ‘abusive overspeed’ fault is still used.

[EuropeanAM]

Please take a moment to review the Forum Announcements and provide the Required Info when posting. Thanks!

As suggested above, max RPM is 7000.

The only way for you to know for CERTAIN would be to either see a fault on Smartcraft, feel Guardian reduce engine power, or have the engine placed on the G3-2018 CDS to read/print Fault History, Counters, etc.

[ToffenG]

Hey,

No fault on Smartcraft. No reduced engine power felt. However, in some forums (incl OffshoreOnly) some says the rev limiter hits in higher, other says a soft limiter hits in at 7060.

To get the rpm down I need to add 0,5 inch pitch to the prop if the rpm needs to be spot on 7000 to a) get max hp and b) not over rev. Merc Racing does not add pitch, so I have to find a good prop shop to do so.

Its a luxury. I never beleived we should go so fast with this propeller.

Thanks :)

Cheeers, Toffen

Please take a moment to review the Forum Announcements and provide the Required Info when posting. Thanks!

As suggested above, max RPM is 7000.

The only way for you to know for CERTAIN would be to either see a fault on Smartcraft, feel Guardian reduce engine power, or have the engine placed on the G3-2018 CDS to read/print Fault History, Counters, etc.

[EuropeanAM]

While there is a stated max RPM of 7000, the limiter should not be viewed as a "fixed" figure- rather as a window of approximately 400 RPM's. Depending on a number of conditions (such as load, and how rapidly you are approaching upper RPM's), the PCM may limit EARLIER to prevent what it perceives as an impending over-speed condition.

[ToffenG]

Hey,

Thanks so much. The reccommended rpm is 6400-7000, but many places I read the engine makes full horsepower at 7,000. So if I am correct, I should tweak my prop so I will be as close as possible to 7,000? For instance 6,980 rpms :)

Cheeers, Toffen

[davidwademarine]

If you’re trying to narrow it down to one prop, you’ll want 7000 RPM with a light load during cooler weather. You also want the prop to get you on plane fully loaded during the heat of the summer. Upper RPM will certainly be lower during the summer, probably up to 5-600 RPM lower.

Propping is the worst part of a repower project. So many options, there’s no ‘perfect prop’, and testing a prop is usually much easier said than done with very few testing programs available. Good luck.

[Wheelman]

If you’re trying to narrow it down to one prop, you’ll want 7000 RPM with a light load during cooler weather. You also want the prop to get you on plane fully loaded during the heat of the summer. Upper RPM will certainly be lower during the summer, probably up to 5-600 RPM lower.Propping is the worst part of a repower project. So many options, there’s no ‘perfect prop’, and testing a prop is usually much easier said than done with very few testing programs available. Good luck.

I agree, if you "gear" it for the top of the rpm range when cool and as light as you'll ever fish then it still should within that window albeit on the lower end when loaded with partners/fish and in warmer weather. Otherwise you need to have a summer/tournament prop that is one pitch lower.

[gehol]

I am going out on a limb and suggest the OP is not doing a lot of fishing in a Phantom 25. LOL

[bshort]

I am going out on a limb and suggest the OP is not doing a lot of fishing in a Phantom 25. LOL

Bet he likes to troll with a down rigger too.

[Wheelman]

And he probably only takes it out in fair weather, but for others on this bassboat central forum who may be reading and looking for advice on propping a boat as they don't understand how atmospheric conditions affect things is why I mentioned it. Most bass boats with a 400R aren't fishing tournaments as they're typically not allowed, but I've met plenty of people who load a boat down and then are lugging it outside of the recommended max range or are all over the limiter when light and winter as they set it up in the summer and loaded with the family. Obviously the OP seems to know what he's doing, but there are many with bass boats here reading the posts trying to learn. My apologies to the OP if he felt I highjacked his thread. I wish that outboard manufacturers would state the rpm of max hp and the what the rev limiter is programmed to as it'd make things easy, but they like to keep so many things secret it seems. A data log as in the automotive world can show you missed a shift and blew a couple hundred rpm through the limiter as like if you unloaded the prop jumping a wake, if you're creeping up on it at max hydro/aerodynamic drag limited velocity based on the power your engine is making at that time then you're just going to brush it which isn't harmful as Don mentioned.