Lake boat engine size query

GLC

Hi all, I am considering buying a lake boat and the most common size that seems to come up for sale is 19ft. Thing is I happen to have a 4hp engine and I am just wondering is this too small for use on a 19ft boat?

fergal.b

Hi GLC it is a bit small for a 19 foot, I would look at a 6 - 15 hp but if your engine is a two stroke and you are not looking to use it on big open lakes or at sea you might get away with it.





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GLC

Thanks for that, I may look at boats that come with engines then so.

connel42

Hi
We have a boat hire business on Blessington Lake
Most of our boats are 19ft lake boats with 4 HP Yamaha short shaft 4stroke
We have found this the best combination for hire customers and the engine can push the boats into heavy weather fully laden with fishermen and gear
However if I was using the boat for private then I would go bigger
The max we can have on Blessington Lake is 6hp which would be good but for boat hire it's just too fast and heavier on juice
Some guys use 15hp and the boats fly with that on other lakes
Why don't you try your engine on the boat and upgrade later if you feel you need more
Your welcome to come out to us and try your engine on one of our boats if you like
www.blessingtonlakeboathire.com
Connel

Tow

As above, 4HP is fine for pottering about. We had a 6 HP on a 23 foot yacht and changed down to a 4HP as it was lighter. The yacht would be much heaver than a lake boat. The only time it was underpowered was when towing another yacht of similar or larger size.

scuby

some lakes around the country restrict the engine side to 5/6hp, maybe check woth some of the local anglers what the norm ?

HeidiHeidi

As per Tow's post above, we have a 4hp engine on a 23ft 1.25 ton(ne??) keelboat, and it's more than enough to move it around the place.

Only time it's of no use (apart from when it doesn't start, which is far too often :mad:) is in very choppy/rough water when the prop keeps popping up out of the water, which there should be a bit less risk of on lakes. (Yes, I know lakes can get rough as well )

Unless you want to go zooming around the place I'd imagine a 4hp would be fine.

pedroeibar1

Engine suitability for lakeboats versus yachts is not a suitable comparison – the latter have a displacement hull, the former can plane, particularly if they have a hard chine hull (and mostlakeboats do).
Important factors when choosing an engine are weight – lifting it on / off the transom, and if it has a reverse gear – not always available on 4HP engines. Also, if you are using the boat for fishing competitions and want to get from A to B quickly the higher HP is a necessity.
I use a 3HP Mercury on my Avon to get out to my 17ft sailing cruiser which has a 6HP Yamaha. I have used the 3HP on the 17 footer, it works but it lacks reverse gear and more importantly it does not have enough power when you need it and as it is a short-shaft engine it is not great in a swell.
Connel’s post above is an offer I would gratefully accept, were I in your position..

demanufactured

Most lake boats are actually rated for 9.9hp even though we all put up to 15hp on them.
They are a displacement hull. ..not built for speed but built for sturdiness.

pedroeibar1

demanufactured wrote: »

Most lake boats are actually rated for 9.9hp even though we all put up to 15hp on them.
They are a displacement hull. ..not built for speed but built for sturdiness.

Those comments do not make much sense. If most lakeboats were 'displacement hull' there would be no point in increasing engine size, as the engine would weigh the boat down and the hull would still have to push water out of the way. Most lake boats actually are semi-displacement, designed to remain steady in the water at slow speeds and with an ability to plane on the after-part of the hull when sufficient speed is reached. As for being built for strrdiness, most boats built for speed have to be sturdy.

demanufactured

pedroeibar1 wrote: »

Those comments do not make much sense. If most lakeboats were 'displacement hull' there would be no point in increasing engine size, as the engine would weigh the boat down and the hull would still have to push water out of the way. Most lake boats actually are semi-displacement, designed to remain steady in the water at slow speeds and with an ability to plane on the after-part of the hull when sufficient speed is reached. As for being built for strrdiness, most boats built for speed have to be sturdy.

http://www.google.ie/search?hl=en&site=webhp&tbm=isch&source=hp&q=burke+boats&oq=burke+boats&gs_l=mobile-gws-hp.3..0i24l3.2854.9450.0.10934.16.11.3.2.2.0.207.948.9j1j1.11.0.les;..0.0...1ac.1.5.mobile-gws-hp.Md_C_LhmFLU&biw=360&bih=533&sei=qIIvUaXACIywhAfr8YDwDg#i=2
But they don't plane at speed...they dig in and the bow goes skyward.
Unless you modify the hull that is.

I have spoke to many builders of lake boats and they all say 4hp - 10hp is what them boats are designed for.

I have a 15hp four stroke on mine but I have fins made up that are fitted at the stern to give some lift at speeds.

GLC

Thanks for all your help guys, I think I'll go for the 19ft and just see how I get on with the 4hp, if it's no good it's no good. The lakes I intend using it on wouldn't be that overly big so I might get away with it.