Re-powering 17.5 1990 Osprey

[fishinandpickin]

Newbie here trying to re-power my 1990 AS 17.5'. i believe it is an Osprey but not 100% sure. There is no capacity plate anywhere on this boat. I bought the boat 2 years ago and it has a 115 Yamaha 2 stroke. Was wondering if anyone knew the specs for this boat as to weight, persons and Max HP. I was leaning towards a 115 4 stroke but do not want to over weight it. Any help would be much appreciated.

[Capt. Bob]

Welcome aboard. F & P.

Nice lookin' boat

Here's a start.
http://www.classicaquasport.com/gallery ... photo/2873

[fishinandpickin]

Thanks Capt Bob,

I bought this boat about 2 years ago with a very wore out Yamaha 115 2 stroke. I want to put a new 115hp Yamaha 4 stroke but I am worried about the extra weight. If anyone has a similar boat please give me feed back on the 115hp 4 stroke or should I go with a 90hp 4 stroke.

I also want to have a capacity plate put on it so I don't get hassled by the coast guard. this is turning into a hard chore to do.

I am going to put on a jack plate and was wondering what everyone thought about putting an 25 inch shaft motor on it instead of the standard 20" that is on it now. a buddy said he would put a 25" shaft on it because it would get it up out of the water more.

[RickK]

Welcome aboard fishinandpickin  :!:  :!:
I would check the weight on the 4Stroke versus the weight on the same HP 2Stroke.  These little Ospreys are not designed for big weight on the transom - even if it says it's good up to 150hp.  I think everyone's scuppers are under water ('cept Marc's) with anything bigger that a 70hp 2 Stroke.  There ways to combat it but you can't beat it.  The more weight the lower the aft will sit.  Plus putting on a jackplate will push the center of gravity backwards that much more....  If you must have a 4 stroke, maybe try a 4Stroke 70?

[seabob4]

Thanks Capt Bob,

I bought this boat about 2 years ago with a very wore out Yamaha 115 2 stroke. I want to put a new 115hp Yamaha 4 stroke but I am worried about the extra weight. If anyone has a similar boat please give me feed back on the 115hp 4 stroke or should I go with a 90hp 4 stroke.

I also want to have a capacity plate put on it so I don't get hassled by the coast guard. this is turning into a hard chore to do.

I am going to put on a jack plate and was wondering what everyone thought about putting an 25 inch shaft motor on it instead of the standard 20" that is on it now. a buddy said he would put a 25" shaft on it because it would get it up out of the water more.

The 115 4-stroke comes in at 402 lbs., the 90 and 75 at 369.  32 lbs difference.  And I doubt there is that much difference between the new 115 and the old 115 2-S.  A lot of the parts on the newer 4-strokes are plastic (don't get me wrong), which have considerably reduced the weight.

If you put a jack plate on her, stay with the same shaft, 20".  That's what the 175 was designed with.  When you jack the motor up, you will get the prop nearer to the surface, so then you can play with props, probably a larger diameter 3-blade for more surface area, or even a 4-blade.

Hope this helps.

[akbridge]

I have a jackplate on my 170.  Its a nice feature to have if you fish shallow.  I am running an older 90 evinrude that weighs 315lbs I think.  So my scuppers are always below the surface of the water.  I plug them and don't worry about it.  But that's just me.  I will say the boat tends to porpoise a bit since it has so much weight back there.  Just figured I would mention the porpoising.  I have no capacity plate on the boat either, so I can't help with that.  I think the boats are rate for 5 or 6 people and 115 hp max.  I would suggest that you looking into an Etec 90.  The hole shot on those motors is AWESOME!! and top speed is good.  And it weighs 320 lbs.

[Marcq]

I think the best engine for that boat would be a 2 stroke Yami 90hp at 260lb

Marc..

[RickK]

My 2stroke 115 Johnson weighs around 320lbs and my scuppers have never been above the water line since I've owned the boat.
I agree with Marc - for the 3-5 mph the 115 gives....

[fishinandpickin]

I am all confused now on the way to go. I have talked to several people and they all have great points.

My 2 stroke 115 hp really brought the boat alive and had tons of power. The only problem I see now is that the self balers do allow water in the back of the boat when 2 people are back there. ok so I plug them up, no big deal, live with it and hammer down.

Now if I go with the 4 stroke I am going to have to drop down to a 90 hp to match the same amount of weight. The only problem now is I have a good reliable vessel finally, only its a little slower and does not plain out as quick.

or do you really go against the durability, warranty and resale value of the Yamaha and put a 2 stroke 90hp Yamaha (save a thousand dollars) or the real big question EVINRUDE.

I do enjoys everyone's opinion because I can see from guys that have been boating all their lives and me just under 5 years. Thanks everyone.

[sarasota3phase]

I have a 90 HP Nissan 2 stroke on my 1976 170, and I have the same issue with water coming in through the scuppers when i step into the back of the boat.  I have also plugged them.  I ran into a gentlemen here in Sarasota that did the same thing, then just added a bilge pump in the scuuper well at the transom.  He tells me that if water washes up into the boat, he just pumps it out.  If you do lose any planing ability with the extra weight, take a look at the Smart Tabs.  I put those on my boat about a year ago.  Took 30 mins and what a difference in planing, and totally eliminated any porposing.  You might take a look at the Tohatsu or Nissan 115 TLDI engine.  Still a 2 stroke, and one of the most reliable commercial marine engines in the world.  Would address the weight issue to a degree.

Mickey W
Sarasota, FL

[akbridge]

I agree with sarasota3phase.  There are too many new reliable two stroke direct injected engines out there to not consider them: Etec, Opti-max ( not my favorite but they have come a long way), tohatsu (the same as an optimax injection system), nissan and I think there are a few more.  There is too much hype about fourstrokes on boats.  Two strokes make great power per weight, last much longer than older two smokes, don't smoke, and do cost less to maintain ( just look at how much a yearly service is on a the yamaha four stroke).  Just my two cents worth...

[RickK]

ACTUALLY.... The service manager at the marina I get both my engines serviced at told me that I should be happy I have older motors because of what the ethanol is doing to the HPDI engines.  She said that the injector screens (or something like that) get clogged by the debris loosened by the ethanol and there is no way to clean them - have to be replaced - at about $800 + 4hr labor.
Something else to think about is getting the old motor rebuilt.....

[Marcq]

ACTUALLY.... The service manager at the marina I get both my engines serviced at told me that I should be happy I have older motors because of what the ethanol is doing to the HPDI engines.  She said that the injector screens (or something like that) get clogged by the debris loosened by the ethanol and there is no way to clean them - have to be replaced - at about $800 + 4hr labor.
Something else to think about is getting the old motor rebuilt.....

Read about this not long ago but can't remember where   I think it's the fuel pressure regulator screen but not sure  

Marc..

[RickK]

Plus she said she gets in new motors every day with that problem.  Damn ethanol.  Wait until they ram E15 down our throats....

[seabob4]

Plus she said she gets in new motors every day with that problem.  Damn ethanol.  Wait until they ram E15 down our throats....

I was born and raised in Chicago.  Not that far out of town are farms.  Now, that's what those people chose to be their livelihood...yet for as long as I can remember, those people have been subsidised by whatever government was in place to protect the prices of the crops they grew.

Now it's the use of grain (or corn) alcohol being infused in our gas...

Where was the effin government when the Japanese and Belgians were dumping their steel on our shores, and US Steel, Bethlehem, Interlake, etal., were going under?  In Chicago, the primary industry was steel.  US Steel's "South Works" plant, southwestern shore of Lake Michigan.  Made Ford's River Rouge plant look like a playtoy.  Shut down because of what the government didn't do to protect the steel industry, unlike what they do to protect the farmers.

Off my soapbox now...calm down, relax, have a beer...AND I BUILD BOATS FOR A LIVING!!!

And now E-15...