Replacing outboard motor

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sharky300
Posts: 64
Joined: Mon Apr 07, 2014 1:50 pm

Replacing outboard motor

#1 Post by sharky300 » Sun Jun 05, 2016 8:14 pm

Ok- since adding oil injection to older unit is not cost effective, and I would like to upgrade to something with a little more kick, and more fuel efficient anyway. What do I need to know when shopping for newer engine? (Because that is cost effective...Hahahah)

I have an old 88 SPL Evinrude on it now... I would like to go to a 4 stroke if possible, and get up to about a 150 hp.

Will the 150 be a lot heavier?? Don't want to be riding around with the nose up in the air... If so, what size can I go up to?? Also, I have noticed 20" / 25" in a lot of the descriptions, what does that mean, and how do I know what I have??

If it matters - boat is 24' Gruman funship with 23" logs-

Thanks against!!

Jason

Bamaman
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Joined: Fri May 06, 2011 1:44 pm
Location: NW Alabama--Tennessee River

Re: Replacing outboard motor

#2 Post by Bamaman » Sun Jun 05, 2016 8:57 pm

We're familiar with your Grumman pontoon.

The most horsepower your boat would need is 115 hp. Any larger engine would be wasted money due to weight and the fact that your boat's going to max out at around 30 mph no matter how much power you throw to it. They just hit a speed wall at about that point due to pontoon nosecones are plowing through the water.

If you were wanting to maximize performance, a good used 2 stroke motor will out accelerate and perform the heavier 4 stroke outboards. Top speeds should be about the same, however. Spending $8-9K on a new 4 stroke 115 hp would be too much to spend on such an old pontoon boat.
'12 Bennington 24' SSLX Yamaha 150

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teecro
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Location: Sunset Bay, TN

Re: Replacing outboard motor

#3 Post by teecro » Mon Jun 06, 2016 3:06 am

Can't hardly disagree with Bamaman on his info but I'll comment further for the sake of argument.

First off you'd need to find your name plate data as its best to not hang too big of a motor on a boat; for shits I'd myself would like to know the weight of your old 88 V-Four motor. Truthfully I wouldn't be surprised if your couldn't dam near save some weight by going with Mercury's new class of 2.1 Liter 4-Stokes with up to 115 HP it only weights in at 359 pounds and a Command Thrust only claiming 363 pounds. The 20" & 25" reference refers to foot length and most all smaller diameter pontoons would use the 20" foot length with your's included.
T CRO
2017 Berkshire CTS 24 RFX with Yamaha F150/Simomized 200
2015 Caravelle 16 EBo with Mercury 90

RcgTexas
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Joined: Wed Jun 18, 2014 6:37 am
Location: Texas

Re: Replacing outboard motor

#4 Post by RcgTexas » Mon Jun 06, 2016 6:48 am

I respectfully disagree with the too old boat to repower idea. If your hull is sound(logs) . A new motor is the way to go. My boat is 1995 and used in salt water, its no bathing beauty, but its sound and the tubers and fish don't care. It is a little upsetting to my banker that I don't have a damned 40 k note on it but it does what I need it to do, and its paid for. Repower and save your money to give to the government for medical care. :roll:
1995 beachcomber conversion to tritoon with Honda 135 ,

Link to rebuild [url=http://www.pontoonforums.com/viewtopic.php?f=16&t=19016][Knot Normal][/url]

God Bless America

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Mel85CJ
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Joined: Thu Apr 07, 2011 10:34 am

Re: Replacing outboard motor

#5 Post by Mel85CJ » Mon Jun 06, 2016 9:43 am

We had a Johnson 88 SPL (same motor) on our 1985 Harris 24' flotebote (23" tubes also)

We replaced it 2 summers ago with a Yamaha 90hp 4 stroke with new controls also.

It made a HUGE difference. We are able to pull two tubers and even two adult waterskiiers with it. So much quieter!

The fuel economy savings was unbelievable, I would say we get 2x the time on the water with the new motor vs the old one.

The data plate specs for our boat maxed the hp out at 115hp - we just went for the 90 because we felt it would be enough for our use, and it certainly is. (Lake in Maryland - use it for family recreation).

As someone mentioned, you will want to check your data plate, or look up your specs to see what the max hp for your boat is... I would guess it would be 115hp.

We totally rebuilt our boat this year, and now we have pretty much a new boat, with a 2 year old 4 stroke yamaha on it, it is rated for 17 passengers.... we would have probably $50k+ in getting a brand new boat like that.

Happy pontooning!

Melanie
2001 Riviera Cruiser Regatta 2525
1985 Harris Flotebote Heritage 240
1994 Playbuoy Challenger 20 DLX
Deep Creek Lake, MD

sharky300
Posts: 64
Joined: Mon Apr 07, 2014 1:50 pm

Re: Replacing outboard motor

#6 Post by sharky300 » Mon Jun 06, 2016 2:26 pm

Awesome info everyone- Thanks!!

I'm not looking to get 40-50 mph in this old sled... but I would like to squeeze out a little more out of her. If I hit 30 - I would feel like speed demon. Right now I am running @ 19mph with a wind behind me!! If I get 22-25- I would be a happy man. If it would pull me up on a set of ski's I'd be ecstatic- (@ 6'4" -280lbs- wouldn't count on it!!!!)

I am mainly looking for better fuel efficiency and try to get away from mixing oil and gas by hand... Figured while I was looking- why not up the power a little. I have no marina close to where I camp and boat the most... so I am dragging 5 gallon buckets of fuel and mixing oil- seems like more than I am out on the water!!! If were are going hard and heavy, I might go through 30 gallons a day!! (I know - Quit whining) ha ha

I think the boat is worth spending a little money one- Just re-decked, new carpet, new electrical last year. toons seem to be in good shape- I left it in the water for 15 days on the last trip- and still floating!!! I like the set up of the boat. Not sure I'd drop $10K on a new engine, but if I poke around enough, I would think I could come across something for $2k-$3k??? maybe a little more for the right one.

Thanks again for the info!!!

Jason

Harvey
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Joined: Thu Mar 03, 2016 8:59 pm

Re: Replacing outboard motor

#7 Post by Harvey » Sun Jun 12, 2016 9:53 am

I upgraded my engine this year, I have a 2007 E-Tec with 115 HP, all controls, wire harness, oil tank, prop. Turn package $ 4500.00. 252-339-4560. North Carolina
2007 Party Craft tri-toon
Mercury Verado 250 hp
50 mph

Bamaman
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Joined: Fri May 06, 2011 1:44 pm
Location: NW Alabama--Tennessee River

Re: Replacing outboard motor

#8 Post by Bamaman » Sun Jun 12, 2016 12:55 pm

My local dealer is not very popular with other Mercury dealers in a 1000 mile radius. And he sell's motors all over the U.S. onlline.

JacosMarine.com is about 80 mi. south of Nashville, and he's very aggressive. He sells Lowe pontoon boats, but his pricing is less than any comparable brand--far less.
'12 Bennington 24' SSLX Yamaha 150

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sanfordturbo
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Location: Lake Lanier Georgia

Re: Replacing outboard motor

#9 Post by sanfordturbo » Mon Jul 11, 2016 8:35 am

I am in the same situation with my battle cruiser. However, since the 2cycle is still working and absolutely refuses to die, I will hold onto it.

During my research, I was able to find a few online speed calculators. The instructions are not very detailed, but you can figure out your "constant" if you know the other 3 values.

http://www.go-fast.com/boat_speed_predictions.htm

Put in what you already know: Weight, HP, Speed. Then press calculate above the "constant". Next, change the HP to a larger motor and press calculate above "speed".

There are several other online calculators with more details and variables, but they are all pretty close in results.
1998 Suntracker Party Hut
Force 75hp 2-cycle outboard

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