Would a 50HP be good enough for a 24-footer?

[chrisg]

Just heard back from the marina, my new '87 merc 115 has low compression on 3 of the 6 cyclders, not worth fixing ( wiring insulation is falling off of it also).
He said what I paid for was the pontoon itself.

So he has a 50hp Johnson '99 for 2.5k installed. I have a runabout, so dont need speed, but don't want underpowered either.

ideas?

thinking of just running it till it dies. (Its only a river - 10mi long, cant get to far if it breaks down)

I said I'd let him know in the morning.

 

[Silvertip]

Re: Would a 50HP be good enough for a 24-footer?

There are a gazillion pontoons that size with that exact motor but they also don't go very fast so while it will push the pontoon, it will need to be at nearly full throttle most of the tiime to make any reasonable headway. I would certainly look for a 60 minimum on that size boat. An ideal setup would be a 60 Merc Big Foot with a 14 inch elephant ear four blade pontoon prop.

 

[rogerwa]

Re: Would a 50HP be good enough for a 24-footer?

I'd look around.. I put a 90hp on my 25' last year for $1795. I would look for a motor you can just hang on the back and reuse your controls. Mounting is very easy if you don't need to replace controls. Its not that hard even if you do have to change controls. Just rent a engine hoist and bolt it on.. Check on craigslist, there are motors on there all the time.

50hp would do fine, just don't expect to water ski. My 25' toon came with a 40hp and was OK if just crusing. The 90hp is much better though..

 

[chrisg]

Re: Would a 50HP be good enough for a 24-footer?

Thanks, Does anyone know of good places to find used motors? what is craigslist that rogerwa is refering to?

I wonder - even though it has low compression, it still runs ( just hard to start) perhaps I suld just keep running it till it dont run no more.

 

[elark7]

Re: Would a 50HP be good enough for a 24-footer?

Chris,

Before looking for a motor post your engine problems under the mercury engine forum. You will get lots of tips as to how to fix the low compression without big bucks output. One would be to run seafoam to decarbonize your motor. I am doing that now with my '72 115, with very very low compression on one cylinder. You will also be told that it needs a rebuild. Final decision is yours but check out the options before giving her up for dead. If you decide to get rid of the 115 PM me and if you arn't to far I may entertain a road trip to buy it from you. I really like the old inline 6's. I currently have 2 running and 2 parts motors, plus 3 other old 650 inline 4's. Nothing runs like an old merc! As for size on the toon, I won't go less then 115 on my 24 footer, I have 6 kids and thier friends to haul and the 65 just would'nt cut it, especially when a storm blows up and you are trying to head into the wind and waves (boy was that an interesting day). Just moho.

elark

 

[chris mandella]

Re: Would a 50HP be good enough for a 24-footer?

i recomend you buy a compression test set.there only 30 or so bucks i got mine at c.a.p autoparts.test the engine yourself not hard to do.if your skilled in mechanics,remove the heads and decarbonize that topend use a good brass bristle brush and steel wool with carb cleaner or wd40 works too yamaha sells a prouduct called ''ring free''its about 15 bucks a bottle but it works wonders next best thing to marvel mystery oil. id soak the edges of your pistons with this while the heads are off .take a clean paint brush and brush ring free around the cylinder walls so it works its way into the rings, it should help loosen the stuck rings.scrub the heck out of those piston tops and cylinder heads.dont try to cheapout ,buy new gaskets.ring free is to be mixed with gas so dump the rest of it in your fuel tank and run it.re check the compression now.unless the cylinders is scored up this should have bumped up compression across the board. if you cant do this yourself well-------dont worry the the guy at the engine shop$ gonna love you$.

 

[chrisg]

Re: Would a 50HP be good enough for a 24-footer?

Thanks for the glimmer of hope. I have it out of the water, the guy charged me 1 hour time. I stopped by another marina on the way up to my cabin, Told him the situation, and he said to bring it in, he'll check the compresson for free, as that takes no time. The reason I took it in was because it was making a rattling sound under load. But it does have power ( got up to 20MPH) just hard to start.

Just heard form the other guy as I was typing this. The engine's compression is in limits. the top 2 carbs are leaking, but after he replace the plugs with the correct ones, and adjusted the carbs, it starts up and runs! ( The leaking Carbs may be why its hard to start, and should be fixed).

So he will take it to the lake and test it out tomorrow!

Its always good to get a 2nd opinion!!!!!

I'll let you know the outcome tomorrow, I'm happy(er)

 

[OldePharte]

Re: Would a 50HP be good enough for a 24-footer?

Thanks, Does anyone know of good places to find used motors? what is craigslist that rogerwa is refering to?

I wonder - even though it has low compression, it still runs ( just hard to start) perhaps I suld just keep running it till it dont run no more.

Craigslist is an international set of classified ads and forums. They have listings more localized by city. See - http://www.craigslist.org/about/sites.html

You will have to register. However, if you sell, they post a craigslist e-mail address for buyers to contact you.

I have sold a bunch of stuff on my local boards as we are getting ready to move. I didn't want to trash them. For example, I replaced three windows and was left with three sets of storm windows that I didn't need and didn't want to send them to a trash dump. So I listed them for free and within 1 day, they were gone.

They do have a boat section and in my area, one can buy/sell boats, motors, and parts.

 

[quantico]

Re: Would a 50HP be good enough for a 24-footer?

Hope you can save your current engine as it sounds reasonable to do so. FYI I have 40 hp on a 21 foot pontoon on a river and my next door neighbor has a 50 merc on a 24 foot pontoon. I can hit 18 mph with the top off the boat, can get to about 15.5 - 16 mph by myself with the top on and with six people can still hit about 12 mph. That is fast enough for most river use and can even pull kids around on a tube as long as you are not looking for a super thrilling event.

Horsepower on a pontoon boat is a tricky thing. I had a 25 on my 21 footer when I purchased the boat .I was able to hit 15 mph with one or two people with the 25 , but with more people the speed slowed. The 40 hp I have now was more prop ( 10 pitch ) that my old 9 pitch, but the engine is heavier and now has a power tilt unit that weighs maybe 80 pounds as well. I like my current setup a lot but think that going with a 60 - 75 hp outboard would only give me a few more mph and use a lot more fuel.

Being on a river like myself I would think that just getting on the water is the fun and the speed is not that big a deal. a 50 hp outboard ( if you head in that direction ) would be fine.

 

[chrisg]

Re: Would a 50HP be good enough for a 24-footer?

Thanks, all for your help.

looks like the motor is going to be OK. ( At least thats what this other mechanic said- the owner said I am the 2nd guy who was told that his motor was toast, but all it needed was some minor fixing). he indicated that the 'needle' seat(?!) in the top 2 carbs are leaking and need replacing, and thats why its hard to start.
So it looks like I get to keep this monster of a motor. ( Perhaps we just need to wear ear plugs while driving.)

Also, I figured that currently it gets 2.8 MPG, which is what I saw a newer 2-stroke gets. Goes through 5 gal after crusing ( 15 MPH) down the river and back up - a 14mi trip. - just need a bigger tank.

and PS, I checked out this Craigslist site, even the marina up here is on it selling boats.!

 

[quantico]

Re: Would a 50HP be good enough for a 24-footer?

That is typical for a wide open pontoon boat ( your fuel useage ) I would suggest that backing off the throttle to about 75 percent power will use about half the fuel of wide open. My neighbor with a 50 hp on a 24 foot kayot pontoon uses about 6 gallons for two trips up and back the river... 3.5 miles each run x 4 times... = 6 gal / 14 miles... if he backs off to about 75 percent speed he can get three runs or 21 miles from that same 6 gallons... It seems a good tradeoff in my opinion... although speed is fun and I certainly understand getting the boat as fast as it will go... it is fun.

 

[chrisg]

Re: Would a 50HP be good enough for a 24-footer?

That is typical for a wide open pontoon boat ( your fuel useage ) I would suggest that backing off the throttle to about 75 percent power will use about half the fuel of wide open. My neighbor with a 50 hp on a 24 foot kayot pontoon uses about 6 gallons for two trips up and back the river... 3.5 miles each run x 4 times... = 6 gal / 14 miles... if he backs off to about 75 percent speed he can get three runs or 21 miles from that same 6 gallons... It seems a good tradeoff in my opinion... although speed is fun and I certainly understand getting the boat as fast as it will go... it is fun.

I guess I will have to try and be disciplined, and driver the entire river at 10MPH and see what distance I get. But it is hard to do when you know you can go faster! ( see my posting about 'found the motor I want')

Also, I guess I cant complain if some only have 3.5 Mi for river to run on. I guss this is all you get in the mid west. I should change my signature comment!

 

[Boatleech]

Re: Would a 50HP be good enough for a 24-footer?

A friend had her 50HP Yamaha cut off a 24' pontoon a while back and got a '94 Mercury 40HP to replace it. It was one of those "bargain" motors... We've had to put a few bucks into to get it to where it's reliable, but it does move the boat adequately for the 400-acre lake we're on. Another friend has a 24' with a 25HP Honda on it, and he's very happy, bragging that nobody on the lake can go slower than he can.

OTOH, I see some people with grossly overpowered boats towing multiple skiers, so I guess the bottom line is it all depends on what you want to do with the boat.

 

[chrisg]

Re: Would a 50HP be good enough for a 24-footer?

I've decided to hold out for something bigger.