Motor size help - rigging out 18” aluminum boat

[acoastalbender]

Back in the 90's I lived at elevation and had a Gruman 17ft aluminum boat with a 60hp Johnson 2st on it ... it was a great set up, managed close to 28-29mph (at elevation!) and a quick enough hole shot ... that same set up would do 35+ at sea level ... I don't think you'd need any more than a 90 on that ...

[bwguardian]

Originally Posted by sgrem

Those weights are for some older motors....the newer ones are a bit heavier.

I run a 90hp four stroke on a 20.5ft aluminum boat with 99" bottom with float pods and jack plate and up to 7 big biscuit heads. Motor weighs 400# I think.

If you are wanting it to run shallow I would say a 60-90hp. If more bass boat style I would say 75-115hp.

The original post stated a 2004 Mercury 125, which is an ELPTO 2 stroke. They did not make anything other than that for this year model...

[johnnywalkerred01]

Thanks guys.

I’m going to try and find a 3 cylinder 2 stroke 70 hp since I’m familiar with the engine, I like the light weight and I can keep the cost down with this engine. I was just unsure if it was enough to jump on plane and handle a heavy load. From the responses I think I can live with the performance.

So, I’m looking for a 70 hp engine , small aluminum center console and hydraulic jack plate to rig out my project if anyone has something available I Got cash LOL.

Thanks again for the discussion guys.


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[gotmuddy]

Originally Posted by johnnywalkerred01

Thanks guys.

I’m going to try and find a 3 cylinder 2 stroke 70 hp since I’m familiar with the engine, I like the light weight and I can keep the cost down with this engine. I was just unsure if it was enough to jump on plane and handle a heavy load. From the responses I think I can live with the performance.

So, I’m looking for a 70 hp engine , small aluminum center console and hydraulic jack plate to rig out my project if anyone has something available I Got cash LOL.

Thanks again for the discussion guys.


Sent from my iPhone using Tapatalk

another option is to run a tiller and no console. Plus with the yamaha(and likely OMC as well) you can put some different reeds in and make a huge difference in acceleration

[bwguardian]

Originally Posted by gotmuddy

another option is to run a tiller and no console. Plus with the yamaha(and likely OMC as well) you can put some different reeds in and make a huge difference in acceleration

That's what I did to my Mercury 115/125 and it did indeed make a difference...in alot of ways...

[gotmuddy]

Originally Posted by bwguardian

That's what I did to my Mercury 115/125 and it did indeed make a difference...in alot of ways...

I put a set of chris carson reeds in my 40hp jet and removed the limiters on the reed blocks. huge difference.

[PicoPop]

That 3 cylinder OMC 2 stroke is a great motor!!! So is the 3 cylinder 2 stroke Yamaha. I think you would be happy with the performance of either. I went with the 4 cylinder on my boatrigh and regretted it from the start... too heavy and on an alumnium flat bottom hull you are not going to make a giant difference in top end between the two.

[bwguardian]

Originally Posted by gotmuddy

I put a set of chris carson reeds in my 40hp jet and removed the limiters on the reed blocks. huge difference.

Yes, those are the ones I utilized also...Chris is a great guy to deal with!

[gotmuddy]

Originally Posted by bwguardian

Yes, those are the ones I utilized also...Chris is a great guy to deal with!

I agree 100%

[gotmuddy]

Originally Posted by PicoPop

That 3 cylinder OMC 2 stroke is a great motor!!! So is the 3 cylinder 2 stroke Yamaha. I think you would be happy with the performance of either. I went with the 4 cylinder on my boatrigh and regretted it from the start... too heavy and on an alumnium flat bottom hull you are not going to make a giant difference in top end between the two.

I took the 88 4 cyl OMC off my shoalwater when I bought it and put a 90hp yammy on and immediately shaved 70lb off. best mod ever.