new motor for pontoon

[msbrown]

I have been reading this forum and it seems very good,
My question: We have a 40hp 4 stroke mariner 0gb87825b(not sure if it is Long shaft)1998 few hours;
we want to go to a 90 hp mercury. We can get a 2 stroke fuel injected long shaft. Is it appropriate for our 21 foot Southland pontoon.
Our problems were: propeller coming out of water, and going only10-12 mph. We need speed only to get to shelter on Lake Simcoe. It isnt a GOOD lake for pontoons.
Thanks for any help

 

[lncoop]

Re: new motor for pontoon

Most 21 footers can handle a 90. Some newer ones can handle a 115. Your boat should have a capacity plate somewhere that specifies the max hp, but if you're unable to locate it you can contact the manufacturer for verification. http://www.southlandboat.com/00_AN/08_coresspondance/08.php Offhand though I'd say you'd be all over it with a long shaft 90 horse. Welcome aboard.

 

[msbrown]

Re: new motor for pontoon

Most 21 footers can handle a 90. Some newer ones can handle a 115. Your boat should have a capacity plate somewhere that specifies the max hp, but if you're unable to locate it you can contact the manufacturer for verification. http://www.southlandboat.com/00_AN/08_coresspondance/08.php Offhand though I'd say you'd be all over it with a long shaft 90 horse. Welcome aboard.

The plate says 93 hp.

 

[EGlideRider]

Re: new motor for pontoon

A 90 should be a perfect match for that boat.

 

[lncoop]

Re: new motor for pontoon

The plate says 93 hp.

Hmmm. Not trying to be a wise*** I promise, but that doesn't sound right. No such thing as a 93 hp. Are you sure it doesn't say 90?

 

[Silvertip]

Re: new motor for pontoon

Let's make sure you are fully informed on the replacement engine. Is this a "new" engine? If not, you need to be aware that there are 90 HP carbureted engines which are OIL injected -- not FUEL injected. Only the Optimax engines are two stroke FUEL injected. Make sure you understand the difference. Those will be long shaft engines and should be fitted with appropriate props for pontoon service.

 

[lncoop]

Re: new motor for pontoon

Msbrown, I suspect the motor you're looking at will be fine for your barge. If it is fuel injected that's great, but a carbureted engine will still do the trick provided it meets emissions requirements in your neck of the woods. I have no idea what those requirements are, but I get the feeling they're a little stricter in Canada (I assume that's the Simcoe you boat on), so take care not to pull the trigger on a motor the government won't let you use.

 

[Jeep Man]

Re: new motor for pontoon

The 90 should be perfect. If it is an older model you may find it a lot harder on fuel. Whatever else, it HAS TO BE a long shaft. Mariner controls will work on a Merc but you may need an adapter harness, depending on the year of each. What years are you dealing with? Your right about Simcoe not being a pontoon friendly lake. I've been out there in 4 ft. swells and that was in a V hull. No way would I take the pontoon out there. It can churn up fast.
BTW msbrown, welcome to the forum.

 

[msbrown]

Re: new motor for pontoon

Sorry it is oil injected not fuel. The 40 we have is a 1999 and the other is a 1995. I am leery on the exchange. R there things to look for.THANKS for the welcome. WE know very little about boating.

 

[lncoop]

Re: new motor for pontoon

There are definitely things to look for, some of which have already been mentioned.

1. Emissions. You're considering swapping a four stroke for a two stroke. Will the two stroke comply with emission regs on your lake? You really need to have this question answered first. Check with your DNR. All other questions are irrelevant until you answer this one.
2. Compression. It should be 90 psi minimum (some might say higher, but it's a fifteen year old motor) and should have no more than 10% variance between cylinders.
3. Oil injection. Again, it's a fifteen year old motor, so the oil injection system bears close scrutiny. The good news is they're pretty beefy on the Mercs, but you want to ask questions about it. Has it been replaced? Disabled? Has it ever failed? If so, that could have resulted in engine damage.
4. Water Test. This may or may not be possible, but if it's currently on a rig take it out and run it.

Consensus is logistically the motor would work. You're reaching a point at which you might be better off in the Mercury section. There's world class knowledge of outboards over there.

 

[msbrown]

Re: new motor for pontoon

Does anyone know if iboat.com or edysmarinesuperstore.com are reputable places to buy a motor 90elpt4s is 7150$
WOuld a 25 inch shaft be too long for 6399 at iboat.com
We r Cdn and can find nothing here.

 

[msbrown]

Re: new motor for pontoon

Jeep Man,
I see a CDN. DO you know of a reputable place to buy a 90 hp mercury?

 

[lncoop]

Re: new motor for pontoon

I'm not Jeep Man, but this guy has a pretty good reputation. Pretty sure several iboaters have bought from him. I'm sure he would ship to Canada.
http://smalloutboards.com/