Just so that you all know

[Mike Killay]

On the weekend I tested a 1983 Mariner 2 hp on flat water in a cutting off the Thames.
It developed a bollard pull of 50 lbs.

[Niander101]

DO a test with a seagull?

[Collector Inspector]

Yes!

There should be more of this type of testing.

B

[Adrian Dale]

Change the pitch/diameter of the prop and change the bollard pull.. there are many variables in this type of testing

AJ

[Charles uk]

Exactly AJ.
If you attach a rev counter to your motor when your doing your bollard pull, you will see significantly less revs than when the hull is running free, it's a reasonable assumption that less revs equal less power.

Perhaps that's why Seagull's spring balance was built into a special transom bracket, so it could measure the push when the hull was running free, which would give a more accurate reading.

Though the static bollard pull might be closer to the truth with a 4 : 1 gearbox.

[Mike Killay]

Change the pitch/diameter of the prop and change the bollard pull.. there are many variables in this type of testing

AJ

Is that why the featherweight is only quoted at 45lbs, but the same engine with 40 plus leg is quoted at 55lbs?