Testing under load

[smallribber]

I have an issue with my new to me Yamaha 75 hp 2 stroke and after I have worked on things it needs to be tested under load. I can obviously tow the boat to the nearest water which is a significant faff. I don’t think you could get a tank big enough to test a 75 hp at hig rpm under load.

Is there another way to do this

[Nasher]

I used to visit an Outboard dealer years ago who'd run quite large outboards up under load in a huge water tank, like you get in the loft of your house but I suppose the biggest you could buy.

It had the lid on with a U shaped cut out to limit the amount of water lost over the sides.

[jeffstevens763@g]

Originally Posted by Nasher

I used to visit an Outboard dealer years ago who'd run quite large outboards up under load in a huge water tank, like you get in the loft of your house but I suppose the biggest you could buy.

It had the lid on with a U shaped cut out to limit the amount of water lost over the sides.

Plus they use test props too

[mhill]

Testing in a bucket isn't under load, there isint the same forces on the prop.
I had this argument with a OEM (cant recall which) many years ago and it's one of the reasons why marine engines do not come pre run in. Yes water passes the prop but the engine does not work to the same extent.

I had a lengthy argument with an East Anglia based Honda dealer around this, My BF100 was leaking oil but we could not find where and it was only happening after a protracted time. The dealer tested it but only in a tank for 40 minutes and claimed no issue. It was found to fault after less than 30 mins under a load at sea once a more competent dealer did the job properly.

Ultimately there is no replacement for getting it all wet.