what rpms should i be looking for?

[leoo24]

Hey guys


Was cleaning my prop and saw it was a 19p, so decided to read up about props and read about low rpms.

I've never paid attention to my rpms being too low, i don't generally go wot, like to cruise around coastline (am in east spain).

Next time i'm out i'd like to see what my rpms are at wot, what should they be roughly?

21ft crownline, 4.3 efi mecruiser 19p 3blade aluminium prop, 1800kg dry weight.


cheers

Leo

 

[Bondo]

Re: what rpms should i be looking for?

Ayuh,... 4400/ 4800 rpms at wot...
If you're efi has a rev-limiter, it'll probably kick in at 5000/ 5200...

 

[Silvertip]

Re: what rpms should i be looking for?

Wde open throttle rpm with what you consider an average load should be in the 4400 to 4600 RPM range. It doesn't matter if you never run at wide open throttle. The engine must be able to achieve that rpm because if it doesn't, the engine is considered to be lugging or laboring harder than it needs to. That means the throttle is open farther than it would have to be if the correct prop was used. In other words, if the prop is wrong for wide open throttle, it is wrong for every throttle setting less than that as well. Conversely, if the engine tends to over rev at wide open throttle, you need a prop with more pitch which lowers rpm.

 

[leoo24]

Re: what rpms should i be looking for?

Thanks guys,

am going to keep an eye on revs when i'm next out