Transom HP rating question #7442

Hello everyone.

I'm rebuilding the transom on my 15' Welded Gregor H-51. The transom that was in it has the factory specs on it, where there are two ratings. One for max horsepower of 15, the one below it says 7 max hp.

That can't be right, can it? That's not saying 15 is the max for center console controlled outboard and 7 for tiller is it? It doesn't make sense that this boat would be rated so low. My older 13.5' riveted valco has the same hull shape but is rated for 20hp max.

That's probably it - remote vs tiller. The difference could be the transom height between the two or one had a chine hull vs a flat bottom.

https://www.gpo.gov/fdsys/pkg/CFR-2002-title33-vol2/pdf/CFR-2002-title33-vol2-sec183-43.pdf

Though those regs are from the 80's...whatever preceded them might have been different.

I agree with OTW, must be remote vs tiller steer. I sure would have guessed more than 15 HP for a 15' boat. Based on OTW's link it looks like boats with tiller steer or 15" transoms carried a heavy penalty back in the 80's.

I think I'll throw my 20hp 67' Johnson on it, see how it does. Seems like it could use more power than that since it's going to be loaded to about 800 lbs with people/equipment/etc.

Just out of curiosity does it have a 15" transom?

LDUBS said:

Just out of curiosity does it have a 15" transom?

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Yes sir.

boatlose said:

LDUBS said:

Just out of curiosity does it have a 15" transom?

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Yes sir.

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Aw geez, now I feel really old. :LOL2:

I just noticed you are in Santa Rosa. I hope you survived the fires without too much problem.

PS: I like that tackle shop right next to hwy 101 in Cotati.

The fires sucked. Came very close to us but didn’t get torched luckily!

Those are the current regs that I put a link up to - they came about in the 80's though and the boat he was asking about was older so they might not apply.

Thanks guys for your input/help, I appreciate it. Might revive this thread with speed & load results later. :USA1:

onthewater102 said:

Those are the current regs that I put a link up to - they came about in the 80's though and the boat he was asking about was older so they might not apply.

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It was interesting to me to see how they arrive at the HP ratings.