Merc 1150 question

[KeithAB]

I just purchased a 1978 Glasstron Carlson CVX 16 project boat. Got it cheap. It has a complete 1978 115HP inline 6 on it. Previous owner said the powerpack was bad and that is all. I plan on re-doing this boat to use. Logic tells me to ditch the 115 and go with a newer motor, however I love the old towers of power. Is it feasable to use this motor, given todays fuel and things like that? What are the pros and cons of this motor? Any information is greatly appreciated

[Michael J Giesler]

inline 6's are great motor's in my book just make sure you have a good water pump and run good fuel threw it

[Robby321]

Yep, get a pack, change the impeller, time it at 21 degrees, run good fuel, and run the beast.......

[Mark Poole ModVP]

Another item that is cheap insurance is the use of internal engine cleaner. OMC calls theirs "engine tuner", Merc calls theirs "power tune". Simply spray a can of it evenly into the engine through all 3 carbs. Keeps the rings free and helps prevent hot spots, very important in any engine.

[Mark75H]

I would say it depends on how much of a gearhead you are. If you are not interested in being a mechanic ... 1978 was a long time ago for any motor.

[KeithAB]

Well, I do willingly own several boats, so I have to be a gearhead, or an idiot, one or the other. I just got the boat yesterday, so I haven't had a chance to run compression on the motor or anything yet. I read a lot of stuff on scream and fly and know there is a wealth of knowledge here and just wanted to get some feedback on the motor. All logic tells me to pull it down and build it regardless of the compression, but I would like to get the boat seaworthy and go run it before I move forward. I have heard in the past that the inline sixes are bad about burning the top piston. Besides clean carburetors and good fuel delivery, what else needs to be done?

[Mark75H]

These things Robby told you:

Yep, get a pack, change the impeller, time it at 21 degrees, run good fuel, and run the beast.......

Run whatever is the best gas you can get locally

They are not "as bad" as they are "unforgiving"

Another thing is to use your tachometer and have it propped to get over plane very easily. This usually puts you running 6,000-ish on top end, but its better than burning it up. They easily tolerate 6,200 rpm, but will punish you for running bogged down.

[Robby321]

One thing, if used in salt, I would repower. Torching a piston? Twice done #3 on my old XS150, first time was from plain abuse, hard running at high R's, got some bad gas I guess,
and timing too high. I don't golf, but I "got a Hole in one'!
Dropped it off at a Merc wrench friends, ripped down, rebuilt, and he set the timing as I was running premium gas. Well, I was running regular!
Went out, and it ran like a bat out hell, ..UNTIL...well...another "Hole in One"!
Back in, re done again, and cranked the timing down. Never a prob after that. But that was back in the 70's.
Put together (avatar), a Flatty with a "Frankenmerc" crank up rebuild. Block was a (think) 72 orig 115, which was a choked down 135. Did 135 tuner/reeds/carbs, whatever needed to get back to 135. Broke in at 19 degrees, 25/1 oil, now at 21 degrees timing, and run good 40/1 oil, and premium gas. Many say mid grade gas OK, but for a few cents more, go "large"
Ya need to do a comp check, and a good look over first, before anyone here can give advise. On the Powerpacks, many were torched by a simple idiot..(yep, I did it once too!..DAMN)..not paying attention and hooked up the batt wrong posts! (it was dark, give me a break!) Fried the pack.
You should do all the electrical test first though. Make sure its a pack. Also, on the old black Merc controls, they corrode just inside the key switch. Electrical corrosion problems, over the years, take there toll. So? Well, the boat IS A CLASSIC! Work a bit the Merc, See what ya come up with. If not, stuff a "Big Johnson" on it.
Get some pix up!
And I have a source, all old IL6 parts...he has boxes parts, and many motors, rebuilt, or ready too. Pretty sure a Powerpack box alone is a good $300.
Wish ya well, the old "TOP"...gotta love the Inlines!

[Mark75H]

$206 - $230 for the CDI box, but you have to use an alternator triggered tach with it. Its worth changing to have the new box. The motor will start like new and require less choke, etc.

I have some used ones I will sell for $40 each, but ... they are old and used and will not run "like new"

[Robby321]

Another thing is to use your tachometer and have it propped to get over plane very easily. This usually puts you running 6,000-ish on top end, but its better than burning it up. They easily tolerate 6,200 rpm, but will punish you for running bogged down.

Sam knows his stuff here, and on that quote here, I could NOT agree more.

The LAST thing ya wanna do is bog a IL6.."hole in one"

Again..timing down, best gas ya can get, and don't spin a big blade. I run on the Flatty, 15 1/2 feet, me/boat/motor, top about 8/900 pounds.. a 2 blade, 12x24 cup SS hubless, and on a punch, spins to 3500 starts to grab, drops to 2500, then a missile to 5900. As its a Flat bottom, one inch drop on the chines, and an 8 inch pad, sucks air, and rides it. I can't really tilt it up (motor) at all, as the flatty ..well..does not run a pad, like the Glastron...bow up. I'm about 17 inches up on the transom , SS case, and get good water, and the prop is a good couple inches in the water, so I don't tear up a case, like I did on my old switzer 17, XS150, 14x28 2B surface prop. Nice "rooster"...but beat the hell out the case.
DAMN..I love talking the old school "TOPS!"...

[KeithAB]

Thanks for all the info. I'll get some pics up soon.
Been looking for one of these old Glasstrons for a while, yesterday riding down the road, see one out by the road, stop and inquire, $300 bucks for boat, motor and trailer. Trailer has brand new wheels and tires on it. The motor seems, at least visually in really good shape, wiring isin't corroded bad at all. Boat came from east central texas, doesn't look like it has ever seen salt. Gonna need new floor, transom, etc. etc, but I love a project.
It doesn't have Merc controls, must be some aftermarket one, they are polished with trim on the throttle. If compression is good, gonna change the lower unit oil, put a pack on it and see what happens. If compression is good and it doesn't rattle and knock, would you build it?

[Ronny Jetmore]

really good point about the compression. i don't put time or money into anything any longer without a compression test. i keep a gauge in the car at all times. you never know when you run across a deal and you need to make sure on it before wasting time.

[Robby321]

$206 - $230 for the CDI box, but you have to use an alternator triggered tach with it. Its worth changing to have the new box. The motor will start like new and require less choke, etc.

Yep...upgrade...easy and worth it...(and yep, the cold start ...mines a beast, this year, putting in electric enrichners.)

[Mark75H]

A second thought about the tach ... you might already have a switchable tach. If so, changing over would just be a matter of changing where the tach input wire is hooked on the motor and switching the selector switch on the back of the tach. That would be sweet.

[Robby321]

Thanks for all the info. I'll get some pics up soon.
Been looking for one of these old Glasstrons for a while, yesterday riding down the road, see one out by the road, stop and inquire, $300 bucks for boat, motor and trailer. Trailer has brand new wheels and tires on it. The motor seems, at least visually in really good shape, wiring isin't corroded bad at all. Boat came from east central texas, doesn't look like it has ever seen salt. Gonna need new floor, transom, etc. etc, but I love a project.
It doesn't have Merc controls, must be some aftermarket one, they are polished with trim on the throttle. If compression is good, gonna change the lower unit oil, put a pack on it and see what happens. If compression is good and it doesn't rattle and knock, would you build it?

Well, at 3 bills, the Merc parts alone, would triple that on Ebay. Get some pix, check it out, keep this thread going! Rip the floor, do a solid transom, work the motor if needed, but again ..its a classic boat, and I'm still looking for a "V", Glastron, Sidewinder, 16 feet, as that Flatty mine is a grin, but at 60, my back CANNOT handle anymore "unseen", at hit at speed, in a Flatbottom.."Tuber idiots wakes"..freaking OUCH!