Ideal prop - 28' Landing Craft - Twin Seapro 300 AMS

[Fastrack]

Hey all,

Attempting to prop my Landing craft. Owners manual says 5200-5600rpm and ideally should be in the "upper range".

Brand new motors - SeaPro 300 AMS
First prop tried was Enertia Eco 16x19 - 5240rpm - 52.7mph

Dealer recommended a Eco 17. Briefly was 5640rpm wasn't there for long as starboard hit the rev limiter at 5750rpm - 48.5mph

28' Landing Craft - 10' beam.



Keep in mind I did not buy this boat for Speed (I have the 1989 Formula 292 for that). BUT I want the right prop.

It will be hauling building materials etc..

Where do I go from here? I know there's Mercury Racing Eco's 17.5. I'm surprised to such a large increase from the 19?? Maybe the Tech didn't trim up fully with the 19's?

Ben

 

[cyclops222]

Your props are determined when you have a FULL LOAD of stuff and people in the barge.
Empty barge ? The captain & rev limiters will protect the engines. It is that simple.

 

[airshot]

Watch your fact when not running a load, when loaded, you should be fine !

 

[Fastrack]

Well that makes sense. I was thinking this. But wanted to post to get other peoples opinions.

Any idea why Starboard is so much different? I've read Counter Rotating drives are not as efficient so I guess this is why? Someone on another forum said they had to put a different prop on the RH (starboard) drive? Clearly with a load it'll bring the RPM down.

Is it an issue with the RPM not matching? This is on a vessel view display - so digital readout. This is pretty high tech vs the 1989 Formula gauges (only other dual engine boat I've driven)

I really did not want to raise the pitch as that'll hurt bottom end performance.

For now I'll leave it. See how it does under load. Since I now own these props!

Ben