Inline 6 Mercury questions - cowling interchange?

**bsedwebt** · 05-21-2020, 06:20 PM

I am working on a late 1950's boat and am considering options. I am kinda looking for a CLEAN ready to run 1985-88 115hp 20" inline 6 tower of power Mercury if you know of any. Then I was thinking I could purchase an EARLY inline 6 Mercury and take the cowlings and put them on the newer motor to give it the OLD look. Is this possible? What all what I need to do this? Can I buy the front plate, wrap around cowl and top cowl and just slap them on? I like the polished grab handle look on top and on the lower cowling too - is that a direct swap? Does anyone have these parts for sale or a whole EARLY motor that I can work with? Thanks for any input or direction in my ongoing project.

**FMP** · 05-21-2020, 06:25 PM

Maybe I'm mistaken, thought an adi 115 was recently for sale here?

**bsedwebt** · 05-21-2020, 07:20 PM

yes - good price too - it sold already

**FMP** · 05-21-2020, 08:22 PM

That figures.

**CrayzKirk** · 05-22-2020, 10:53 AM

The 99 CI motors are taller than the 89/93 CI motors. The wrap will not fit as far as I know.

**bsedwebt** · 05-22-2020, 05:27 PM

Thanks for that info - I have no experience with this. SO - what is the OLDEST cowling I can use on the mid 80's inline?

**CrayzKirk** · 05-23-2020, 04:52 PM

1968 Merc 1250... The first 99 Consumer CI inline that I know of.

**Dave S** · 05-23-2020, 08:16 PM

not so.... use a 110 chpme lift off.... w/ a 125/ any newer l6 merc … ya juse need the old style latches

**bsedwebt** · 05-25-2020, 05:20 PM

I located serial number 6524352 -- 115 inline 6 in good shape - can anyone tell me what year it is? It has tan stripes but the 115 logo does not say oil injected and single ram so I am guessing 1984. I hear 1983 and newer are prop rated so I am hoping this is a safe bet for prop rated as I really don't care about oil injection but do want the ADI and better trim unit. I also hear I can put 150 Boysen reeds and 150 carbs on it to punch it up a bit since the carbs will need rebuilding anyway. If I get this motor what else can I do to hop it up a bit since it is at the LOW end of my horsepower needs for a 25 foot boat.

**FMP** · 05-25-2020, 05:41 PM

Put a v6 on it. Yes you could get a little more but it would be porting to xs and maybe high domes and 10 petal reed assembly on the lower pair. The 115 adi is not far behind the xs and would better on the heavier hull. But high domes and the reed assembly on it's own could with proper tune and good fuel could give you a bit more but it's easier to hang a v6 and do custom old style decals.

**bsedwebt** · 05-25-2020, 05:58 PM

This old boat would look nice with an old motor really cleaned up/restored to look old with older cowlings, chrome, etc... so a V6 is not in my search. It is more of a style thing. If I can plane it out and go 30-35 that will suit just fine. I do not want to do any porting, piston replacement, etc.. Right now I am only looking at low hour, fresh water use, very clean 115's 1984-88 so I can use today's 93 octane fuel and not kill it. I have heard that you can put 150hp carbs and reeds on this 115 ADI motor and it already has good porting but a little less in the piston area than the old 150's so they can live on today's fuel. - If I do not do an inline 6 of mid 80's vintage I will go with a new 150 3 cyl Evinrude. OH - my research shows the serial number I found is a 1984 model - so this should be prop rated as far as I can tell.

**FUJIMO** · 05-25-2020, 06:20 PM

keep the motor as it came from mercury. don't change anything. it will run the best this way. cosmetics is up to you.

**FMP** · 05-25-2020, 07:16 PM

leave it stock. That's difficult to say.

**starviper10** · 05-25-2020, 09:04 PM

I'm struggling to find pictures of it right now, but there's a twin rig with late model inline 6 mercs with old cowls on them, painted completely in the correct white. Even has the swept skeg lower units. I think it's a wood boat, with turquoise paint in areas. It's rather unique, as the engines sit inside of a cutout in the boat. I'd say it's a swim platform that wraps around completely behind the engines, but it's not really a swim platform, more of just the continuation of the deck lines of the boat.

I'm personally not experienced with the later model tower of power engines, as my newest inline merc is a 1973. That being said, I don't think it would be a terrible amount of work to modify to get some old cowls on there. There's some obvious differences, like the external connection of the throttle/shift cables on the old engines, vs the internal connection on the later model ones. There's sure to be surprises, but looks like someone got it figured out. I'll keep a lookout for pictures.

Also, might be worth your time to ask this question in some of the facebook groups for the old mercs, as you might get more responses there. I know of a few people just off the top of my head in those groups that likely have both models you're looking to combine within their collections.