Thinking about 140 Looper on my 175

[BMAC1988]

I've been looking and researching for a while on repowering my 175 osprey as my 88 is struggling more than I'd like to get up on plane. I found a pretty good deal on a 140hp Johnson looper motor that I'm thinking about getting, going thru, and putting on. What are you're thoughts? I'm wondering and hoping for not only the obvious increase in power, but for some added fuel economy due to it not working as hard for a given speed. Right now my cruise is 25-28mph at about 3800-4krpm netting me right at 4mpg. WOT is 35mph at 4800-4900. According to my calculations on the continuous wave calculator, the added hp would yield me 43mph, that's a pretty substantial gain IMO.

[RickK]

I think the added weight might be a problem putting the scuppers under water.  Here is the capacity plate for a 175
http://www.classicaquasport.com/gallery/showphoto.php?photo=12303&title=175-osprey-pt-2601-7360&cat=766

[BMAC1988]

By my research the v4 140 looper is only like 50-60lbs more than my 88, still less than any modern v4 outboard such as an etec. Do you think that's too much motor for my boat?

[RickK]

You aren't the first guy who overpowered his boat nor will you be the last.  The quest for speed.
I wouldn't be as concerned about the speed as the weight.  The 140 weighs less than an etec 115?
I think we have a member or two that have installed a 140 on their 175 - do a search and see how they like them.

[BMAC1988]

According to Nada my current 88 weighs 301lbs the 140 looper (with the vro stuff that I'll be removing) is 365, and a 115 etec is like 390. I'm less concerned with top speed as I am to fuel economy and ease of planing off. This style of hull will never be a speed demon and I'm perfectly fine with that. Around or just over 40mph is fine by me long as I can easily get on plane. With myself dad and girlfriend a few weekends ago and associated crap to go out for a day (including 2 coolers) I had to use the tabs to get on plane

[RickK]

I didn't realize the etec weighs that much - wow.

My 90/115 Johnson weighs in a 320 and it put my scuppers under, on the 170.  Maybe in 95 they had redesigned the scupper placement and floor height so an additional 65 lbs may not bother you (figure 40lbs from the 120 HP rating).  I know my 92 230 the scuppers are nice and high out of the water. You can test it by placing some sand bags (65 lbs) on top of the engine and see how it sits in the water.  Then jump in the boat and walk to the rear and watch the scuppers.
On my 170 I raised my floor 2-3 inches to help with this.

[BMAC1988]

yea, while the etecs are light by todays standard theyre still porky compared to these old-school johnson/rudes.

the scuppers are def close to the water and that worries me as well, which is why ive been researching what are the lightest motors with more power. on that trip with my dad and gf I had the 2 54qt igloo coolers sitting in the rear, one under the leaning post and the other sitting directly behind it both filled slap full of ice/drinks fuel tank full, more food and BS than would be needed for a small army, etc. where we stayed had a dock where the boat sat overnight, I checked it multiple times and it never got any water in it, but it was really close, and this was with no people in it. soon as I got in and got at the helm there was a small puddle back there (not bad at all, just some standing water). I could've easily put the second, or both, of the coolers up at the bow and the scuppers would've easily been out of the water for overnight. 

[Georgie]

By the numbers you listed at the bottom, it would seem you are WAY overpropped.  That engine should be seeing around 5500 RPM at WOT.  If so, it would explain why you have trouble getting on plane.  FYI - the old crossflow 88 specials were darn near the perfect engine for the 170.  They had the extra torque of a V4 (vs in-line 3-cyl 70HP) with less fuel consumption than the 115.  You should have NO trouble getting on plane with an 88 (even with a full boat) so something else is likely the root problem.  Let us know your prop size so we can be sure before you start tearing your hair out. Also, can you provide model# or year of the engine?

[RickK]

Those numbers didn't even ring a bell with me  - Guess that's why I am not a Mechanical Master
Good catch Georgie

[BMAC1988]

Prop is 13-7/8 x 17 stainless

[fitz73222]

Hi Brett,
You should be swinging a 17 a lot higher rpm then that.  Do a compression test. Crank the engine over 4 compression strokes on each cylinder. It should be about 125 psi on each cylinder. Look at the plugs when you take them out and look for water, metal fines, or dry from lack of fuel. Normal color should be brown to tan with small amounts of black carbon.

[BMAC1988]

I have not run a comp test yet but I'm sure this engine is down on power as it used to turn higher than that as well as get out of the hole and in plane faster. I grew up with this boat (was handed down to me) and we would go loaded down with mom dad me and my brother with all the associated BS that a family needs for a weekend. And while I remember it struggling, the boat didn't have tabs then and didn't need any other input to lay down and go.

[CLM65]

What year is the boat?  The older Aquasports have been known to gain weight over the years due to waterlogged foam.  A heavier boat could lead to a reduction in speed and RPMs. 

[BMAC1988]

The boat is in my sig. A 95 175 osprey

[wingtime]

I have a 90 hp Ocean pro 60 degree on my 170.  More than enough power.  In fact it will almost stand on end when I pour on the coals.  I have a buddy that has a 140 looper on a 1970 19' Cary Craft CC. It pushes that boat to over 50 MPH.  I think you will be severely overpowered with the 140 looper.