Site for Hot Rodding Mercury outboard?

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Lennyg3

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I know quads, and two strokes respond very well to minor mods. Does anyone offer mods for 2 stroke mercurys? I have a 98 115 Merc 2 stroke ELPTO with a jet foot on it. Anything i can do to give it some more power? Thanks guys
 
The difference is that other two strokes don't have to have such a wide powerband. An outboard needs the wide power band because it doesn't have a transmission.

Screamandfly.com is the site your looking for, for hotrodding your engine.
 
I have also been researching this.. ive been looking at a lightweight flywheel (less weight = more rpm), Reeds from CCM (breathes better = runs smoother).. maybe some finger porting. I have a spare 115 siting in my shop, i might try to modify that one and see if there is any difference..

LonLB is dead on with screamandfly.com, if there is a power mod those guys know it.

Ive also found out alot of the Merc 115's are already tuned as far as they can go.. who knows.. Worst case is i throw a rod threw the block trying..
 
Where did you find a lightweight flywheel? Isn't there a rev limiter on these motors at 5500? If so, how would you adjust for the flywheel and added Rpms?

They also made a 125hp version of this motor if I am reading correctly. What are the differences between the 2?

I did sign up for scream and fly but have yet toget a response...
 
I saw your post on SnF.. you may not even get a response.. ive posted a couple of Q's on there with no replies..

Ive found a place that will lighten and balance the flywheel via cnc machining, ive also found some custom made ones for a hefty price. Also there are aluminum racing ones too..

I have a 1986 Inline 6, no rev limiter and have read about guys spinning up to and past 7K..
 
What is the name of the place or website?

Worst case scenario, what do you think this motor is worth? It runs excellent, but I need MOAR POWA! Lol
 
As for the price of your motor.. a lot depends on how many hours,compression overall shape..

As for the cnc for the flywheel.. local fab shop. Seems like Chris Carson may have the ability.. pm him on SnF.

Have you used the search function at SnF yet? I asked a question piggy backing on a flywheel question and no one responded, ive just done my own research in this matter..
 
Well, the motor has great compression all across the board, and the jet lower is
Brand new and a week old. Only in the water twice. A few scratches on the cowling, but otherwise in great shape. Not sure on hours.

I just ordered the reeds from Chris Carson, so we'll see how that works out for me.
 
Well id say it's worth whatever you just paid for it :)

As for a place to either send or buy your flywheel..

https://www.simonmotorsports.com/

Looks like the can lighten them and balance.. if they don't have one that will work for your application already.
 
Canoeman said:
Well id say it's worth whatever you just paid for it :)

As for a place to either send or buy your flywheel..

https://www.simonmotorsports.com/

Looks like the can lighten them and balance.. if they don't have one that will work for your application already.


I bought it with the boat. lol.

I actually got a response from over on SnF. They, as well as chris carson mentioned that the 125 carbs were an upgrade for this motor that would just bolt on, and give me the additional power equiv. to a 125. That, coupled with the reeds and a flywheel may get me close to my target. here's hoping....
 
fender66 said:
Just out of curiosity....what's your target?


In reality, I just want the boat to plane faster, and pick up 4-5mph. It is slow getting on plane, and I see somewhere between 33-36mph depending on load, water, wind, ect... It's a heavy boat.

maybe it is a stretch, but worth a shot. I will add any updates, and reviews of parts I add.

So far, dealing with Chris Carson, he seems very knowledgeable, and a great person to deal with. I really need to hunt down a set of the 125 carbs though. If anyone has a line on a set of them, i would greatly appreciate the help.
 
Sorry to say but your not gonna gain 4-5 mph out of those mods. maybe 1-2mph 3 if your lucky. From everything I've seen and read the fly wheel will help you get out hole faster. Hard to gain much with a heavy boat. To get the gains you want you'd need to go into the motor. I'm not even sure if you can gain anything with the inline 6's. Alot of people say they're maxed out and it takes alot of time and$ to get any kind of gain. Pull the pump off and take out the casting flaws that will help some. You might be better off selling this motor and buying another motor that has more potential for mods. Don't think I'm tryin to discourage you, I've just telling you what I think I've gathered from site like S&F
All I have to say is good luck and glad to see I'm not the only nut that wants more speed out of outboard jet. :mrgreen:

PS Chris Carson is one of the best guys I've ever dealt with, just a real stand up guy and I would recommend his products and services to any one.
 
Lil' Blue Rude said:
Sorry to say but your not gonna gain 4-5 mph out of those mods. maybe 1-2mph 3 if your lucky. From everything I've seen and read the fly wheel will help you get out hole faster. Hard to gain much with a heavy boat. To get the gains you want you'd need to go into the motor. I'm not even sure if you can gain anything with the inline 6's. Alot of people say they're maxed out and it takes alot of time and$ to get any kind of gain. Pull the pump off and take out the casting flaws that will help some. You might be better off selling this motor and buying another motor that has more potential for mods. Don't think I'm tryin to discourage you, I've just telling you what I think I've gathered from site like S&F
All I have to say is good luck and glad to see I'm not the only nut that wants more speed out of outboard jet. :mrgreen:

PS Chris Carson is one of the best guys I've ever dealt with, just a real stand up guy and I would recommend his products and services to any one.

Well, this happens to be a 4 cylinder model. With any motor, the easiest way to get more mph is to bump rpm, and the flywheel is supposed to be good for 3-400 extra. I had already stated that this may be a stretch, but that's what my goal was. You don't have to be sorry either. You aren't going to hurt my feelings lol. It's the Internet lol
 
I think the "in-line 6" comment was about my Merc..

Im up in the air about what to do.. either sell them both and re-power or try squeeze a cple more mph out of my current.

And yes from what ive read the in-line 115 are spun up to about the max already.. Always fun to tinker though.
 
Canoeman said:
I think the "in-line 6" comment was about my Merc..

Im up in the air about what to do.. either sell them both and re-power or try squeeze a cple more mph out of my current.

And yes from what ive read the in-line 115 are spun up to about the max already.. Always fun to tinker though.

If I was to re-power, I'd throw the highest revving biggest hp 2 stroke on the back that this boat would take. Otherwise I'd just tinker. Lol
 
Like I mentioned before the problem is the lack of transmission. If not for that you could port heavily, and dealing with the shifted UP powerband wouldn't be that big a deal.

As for the OP, keep in mind, anything you do to the BOAT to gain speed will make you use less fuel as well.
Not sure how jet outboards would react to a jackplate.....Maybe would make no difference. On a propped boat, a hydraulic jackplate, and small trim tabs would get you out of the hole and on plane much faster, and cheaper than engine work. Especially on a heavy boat.
 
A jet is normally locked in height.. to high they cavitate.. to low they plow water.. float pods are the best bet for a faster hole shot.. you do lose mph top end due to more drag.
 
LonLB said:
Like I mentioned before the problem is the lack of transmission. If not for that you could port heavily, and dealing with the shifted UP powerband wouldn't be that big a deal.

As for the OP, keep in mind, anything you do to the BOAT to gain speed will make you use less fuel as well.
Not sure how jet outboards would react to a jackplate.....Maybe would make no difference. On a propped boat, a hydraulic jackplate, and small trim tabs would get you out of the hole and on plane much faster, and cheaper than engine work. Especially on a heavy boat.


Well, from what I've been reading, these motors aren't much for high revving and the block and head are cast as one solid piece which makes bumping compression very expensive....

And canoeman is correct about jack plates not really being effective.... The most we can really do is play with the trim slightly.

I'm still on the hunt for a set of 125 carbs though.... That and the reeds should wake it up quite a bit.
 
ya see with a prop engine some things are different I guess.

I'm going to mod mine too, but I don't want to get too crazy. Eventually I do want to add a later big block version of my engine (3cyl OMC) Just because the same power but with bigger displacement should give more grunt down low.

I want to add reeds, and mill the head, and beyond that I'm not sure. I'm heavily leaning towards converting to run on E85, too with re-jetting, milled heads, and advanced timing.
 

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