DIY Lower unit repl & 'fin'?' ---'97 90hp Merc Force Tracker

Snerd

Cadet
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Jan 24, 2010
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Hi all, We have bought our first pontoon, a 1997 27' Sun Tracker with 90HP Mercury Force engine. It needs a lower unit installed (we have already purchased). Any tips or pointers for DIY installers?

Also, my husband has noticed that the back of the engine doesn't have a fin like most outboards. Our old Bayliner Capri (120 Force) had a dolphin fin on it which I understand was larger for performance. That is the kind of fin that seems to be missing on this boat; most outboards seem to at least have at least a small fin but ours does not. Do pontoons need these fins or do the pontoons keep it stabilized? Also, what are they called? Thanks in advance for any help ya'll can offer.

Happy boating! We hope to be happily boating soon.
 
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fastback4

Petty Officer 3rd Class
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Nov 2, 2003
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76
Re: DIY Lower unit repl & 'fin'?' ---'97 90hp Merc Force Tracker

Your 90 hp motor on a 27 foot pontoon will not need a "fin" . Some owners install a fin on motors to accomadate the lack of power trim and tilt. Maybe if you upgraded your engine to a 500hp 572cu.in. big block chevy, yea you might have trouble getting the front end down.......lol
 

Snerd

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Jan 24, 2010
Messages
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Re: DIY Lower unit repl & 'fin'?' ---'97 90hp Merc Force Tracker

Thank you for the info, flashback. I don't think we'd be replacing it with an inboard, so thank you for your help. Yesterday I spent some time with my dad and he explained how to get the oil in the lower unit, from the bottom up so there is no air. We just had new shift cables come in yesterday and my husband is determined to get on the water fast... Problem is that we are in the FL Panhandle and may need to spend some quailty time, not with the pontoon, but with our beach this weekend as the oil seems to be getting closer :(:(:( If there were a crying smiley I would use that one instead. Back to better things, our prop should be in soon!! No clue what the hubby ordered, but it was what the Sun Tracker dealer ordered for us so it better be the right one!

Thanks again.
 

fastback4

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Re: DIY Lower unit repl & 'fin'?' ---'97 90hp Merc Force Tracker

Lower unit oil can be a real mess at times. Try to use caution to avoid spills. I use a iol catch pan and rags. Did your dad suggest you use the 1 quart lower unit oil pump dispenser?
This of course can be bought at most department stores. I've never seen it at Auto parts stores though.
I showed my wife some pictures of the towns, shores, and wildlife that BP distroyed. She's very upset as most of use are.........Tom
 

Snerd

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Jan 24, 2010
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Re: DIY Lower unit repl & 'fin'?' ---'97 90hp Merc Force Tracker

Hi Tom- Fastback, not flashback, sorry (see previous post)!! If I recall, he said the oil can come in a tube and that we should stay away from that and use a pump. Thanks for the tip on where to purchase; we probably would have tried the auto parts store first since it's closest to the house. Thank you for the oil pan mention. It's probably something we wouldn't have thought of until we are ready to fill it up and we don't own one (yet!).

Dad also explained to me how the water flows through the lower unit and how the tubes have to be aligned when installed or the water won't make it to the top of the moter (my words, lol). Made me a little nervous since it took us so long to find the part, but he really did make it sound easy. Just hope he can be around to supervise when do it!

Can't wait to get this baby on the water if it's not all oil. They have asked all recreational boaters not to go through the East Pass (from Bay to Gulf) in Destin because of impending oil and booms. Dad was lucky enough to go out gulf fishing last Wednesday. In case you wonder, NOOO we aren't planning to take the pontoon out there ;)

I wish abcnews.com would stop showing the photo of the pelican covered in thick sludge. It's depressing :(

Sarah
 

Snerd

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Jan 24, 2010
Messages
9
Re: DIY Lower unit repl & 'fin'?' ---'97 90hp Merc Force Tracker

Well, we must have done something right....had 8 hours of sun filled sun yesterday!!! We did have to hire someone to hook up the cables (throttle) for us....We bought a small trim tab since our motor didn't have one. Here is a picture of the boat on the water. I couldn't seem to get it any bigger...
 

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fastback4

Petty Officer 3rd Class
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Nov 2, 2003
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76
Re: DIY Lower unit repl & 'fin'?' ---'97 90hp Merc Force Tracker

Nice boat ya'll got there. Post a picture of this "fin" you had to have. Pictures you upload to a thread like this will have a small size 54kb to 90kb . Once your smaller picture is uploaded i can click on it and it enlarges in another window. Try not to upload a large file say 1 megabit. I use a real easy program for shrinking my pictures called Microsoft Image Re sizer. It's a free download at Microsoft.com
 

N Wolf

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May 17, 2010
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Re: DIY Lower unit repl & 'fin'?' ---'97 90hp Merc Force Tracker

I think maybee she was talking about the trim tab. That would be a "sort of" fin that most motors have. And she did say they just got one.
 
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