Outboard Size

[Grizzlybear]

Hi all

Currently running a 50HP Mercury 2 stroke outboard from 86 on the back of the boat pictured. To it's credit it runs fairly reliably, but it was kept in salt water for at least 10 years coupled with horrendous conservation in the winter time. So she is showing her age a bit around the drev. plus I am getting thick low hanging white smoke pouring out of it, which deduced after reading the FAQ on this forum is not the single best news. But in general she runs grand, particularly early in the season, anyways this isn't a repair question of course.

sadly it's a question of vanity, I am looking for a little more beef. I would like to go 75hp.. poss 80/90. Would much rather a 4 stroke as well. feel free to lambaste me.

the boat its 6.8 meters long and heavy, alas I don't know how heavy. I received no papers with the boat, the state it was in, i was lucky to get a boat

 

[109jb]

Re: Outboard Size

OK. So is there a question??

 

[ED21]

Re: Outboard Size

I would guess a 50 hp outboard is small for a 20' boat. If no capacity plate, you might use the coast guard standards for home built boats to determine a reasonable hp rating. What kind of speed do you get out of your present setup? Any comparable boats in the yard? What do they use for power.
It's a nice looking boat with all that varnished wood.
"showing her age around the drev" What is a drev?

 

[Grizzlybear]

Re: Outboard Size

I measured it with a GPS and registered 14 knots out of it, with just me on board. The drev, sorry I began my boating life in Sweden, so my boat terminology is a mix of Swedish/English, the drev is the lower unit I guess.

I have seen a 75HK on the same model.

 

[tashasdaddy]

Re: Outboard Size

i think a 90- 115 would do nicely on that boat. if the transom is strong.

 

[Grizzlybear]

Re: Outboard Size

Really so much? That's great! The motor does at present feel to small for the job!

 

[ED21]

Re: Outboard Size

I would agree with tashasadaddy about a reasonable size outboard and making sure the transom is in good shape.
I have a 40 hp 2 stroke on a 16 ft aluminum boat and can't imagine 10 more hp on your boat would be near big enough.

 

[Grizzlybear]

Re: Outboard Size

Thanks soooo much for the advice chaps!

Here is the motor in question, certainly there's plenty of space, the transcom is pretty short.

The engine is a short shaft. I am quite worried about increasing the weight, but I really want a bigger motor, silly huh.

 

[Tacklewasher]

Re: Outboard Size

You can't just swap it with that white one?

 

[steelespike]

Re: Outboard Size

If you can do a new motor check out the Evinrude Etec Meets or exceeds all carb requirements.only 2 stroke allowed on lake Tahoe. Relatively light they have a commercial 2 cyl 65 hp 240lbs, regular in a 60. three cylinder 75 and 90hp.320lbs. 20 Shaft length minimum.your merc weighs about 200.

 

[Grizzlybear]

Re: Outboard Size

Thanks for the replies!

A brand new motor is kinda outta my price range... _I was thinking a little more along these lines below. Apologies for the long link, just wanted to translate the page from swedish to english.

http://translate.google.com/transla...348040.htm?ca=11_s&hl=en&ie=UTF-8&sl=sv&tl=en

So if my merc weighs 200 pounds, does it follow that the featured engine is at minimum twice as heavy?