So I took my 2001 Formula 292 with single Innovation Marine 496 to a shop near me ( I don’t want to name the place at this time) For them to diagnose my low power issue below 2800 rpms. They hook it up to the propshaft dyno and tell me they do see that something is taking away power for some reason, but they cannot read the computer because of it being an Innovation Marine computer program. They tried working with Innovation and decided to replace 6 sensors on the engine. Anyways after having the boat for close to 2 months, they call and say it is finished and running good. I pay a $1700.00 bill and take the boat out the next weekend. The same issue is still there, can’t turn a 24 pitch Hydromotive prop past 2500 rpm, the engine is powerless. So Put back on my 25 Bravo FS and spin it to 5500-5600 rpm and the drive blows within a couple minutes. The lower has a cracked case and leaking oil, no engagement, got towed in. My question is, can these propshaft dynos put enough strain and stress on a good drive that it can hurt the drive? My drive fluid was perfect before I took it to the shop. They said they did multiple WOT pulls and testing. My engine is somewhere in the 500 horse range maybe 575 tops. Drive has around 200 hours on it.

What drive?

read the title

Your drive was likely hurt before they even Dyno'd it. Using the propshaft dyno didn't cause your problems.

Unfortunately XR's can go at any moment...

Lol. Was driving and missed that part.

Usually it's the gears that fail but anything is possible I suppose. I'm thinking it may be the prop if you changed and spun the other with no problem.

It sounds like you were loading it kind of hard with the Hydro prop. (probably harder than the dyno) Have you run that prop before?

really makes no sense, you go up in pitch and pickup 2500 rev's.......might be something wrong with the 24

I have run the Hydromotive before. It was a cool day with very light load and at first it was hard to turn The prop but the engine finally took off and spun the Hydro to 5300-5400 rpm low 70’s mph. This time I had full tank of fuel and it wouldn’t spin it past 2500. There seems to be an issue with the engine not making power under 2800 rpm. Once the engine reaches 2800 rpm it takes off and screems. The only way I can get it to reach 2800 is with a prop that slips enough. I’ve tried numerous props. 26 Bravo acts similar to the 24 Hydromotive in rpm and speed. But it’s hard to get it to the 2800.... that’s why I took it to the shop.

I’ve also worked with Bblades and their testing program. Couldn’t spin a 26 5speed then tried a 24 5speed which acted very similar to the 24 Hydromotive P5x.