1970 Mercury 1150 - The story continues (Pictures)

[MercFan]

Hi guys!<br /><br />Serial# 2839467<br />115hp 6cyl Inline 2stroke <br /><br />The saga continues.<br />To bring you up to speed, I have ordered several parts for the carbs. All havn't arrived yet, but I have received the new floats and .064 main jets. All I'm waiting for now is the new seats and gaskets and I'm all set.<br /><br />But in preparation, I'm planning timing etc. according to various other posts on the board. The problem that I will be facing soon is where to set max advance to. From atleast 2 or 3 other posters I'm told that max advance for my engine is 21 deg BTDC. The problem is the decal timing sticker on the casing does not have a 21 deg BTDC. What my dad and myself have finally decided is to basically just setup the motor to run, take it to open water, and run it while adjusting timing. Wherever we get max WOT rpm will be the max advance timing setting.<br /><br />Any comments from you guys will be most welcome. Here's some pics of the engine as it stands now, with a pic of the sticker. Soz for the quality, my phone ain't that great close up.<br /><br />

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[AEROCOOK]

Re: 1970 Mercury 1150 - The story continues (Pictures)

MercFan.<br />Based upon the graphics on this motor, it is not a 1970 1150.<br />I have a 1970 1150,it has red stripes and the engine block is silver, not black. Is it posible that the bracket that has the serial number on it has been changed in the past? I also have a 1974 1150 and yours has more modern graphics than it does, Im no expert, but I put your engine in the mid to late 70s.<br />A clue to the actual year may be the number 115 on the cowl, the earlier ones were 1150.

 

[MercFan]

Re: 1970 Mercury 1150 - The story continues (Pictures)

Thanx Aero!<br /><br />That more or less confirms our theories this side aswell. The motor must be a hybrid. Built up from various components.<br /><br />Best guess would be the cowling, bolt-on chassis and lower unit are off the "newer" original engine, and that the power head is from the older 1970 donor engine.<br /><br />This leaves me without any timing marks. And I assume that if I advance the timing too far the engine will start knocking, and I by tuning the timing for max rpm at WOT should be the correct timing for the engine.

 

[steelespike]

Re: 1970 Mercury 1150 - The story continues (Pictures)

I believe the 115/1150 is famous for needing careful timing adjustment and that there may have been a change(s) over the years.Too much advance can lead to distruction.The boys at Johns Old Mercury Web Site may be able to pinpoint your powerhead and help clear up the mystery of proper timing.I believe also there was much discussion about the proper octane fuel.<br /> With some believeing that a higher octane helped lessen the chance of premature failure.

 

[MercFan]

Re: 1970 Mercury 1150 - The story continues (Pictures)

Thanks Spike,<br /><br />The site seems a bit broken :-(<br /><br />Hope someone here can id my powerhead.

 

[AEROCOOK]

Re: 1970 Mercury 1150 - The story continues (Pictures)

Where are you getting the serial number from?<br />The spot that you indicate in the image may not be correct, The serial number location is between the two transom clamps and about 4 inches up.

 

[MercFan]

Re: 1970 Mercury 1150 - The story continues (Pictures)

The plate between the transom screws has the same number. I'll have a look in the area for a punched number.

 

[emckelvy]

Re: 1970 Mercury 1150 - The story continues (Pictures)

Looks to me like the top shroud with the timing decal is from a different motor, either a M1000-6 or maybe an M-1250-6. Those motors used about 34 deg of total advance. I'd handle the issue one of two ways: either replace the top with the correct one, or verify that Zero deg on your existing decal is in fact TDC #1 for your motor. Then, since the timing increments are even throughout the decal, carefully measure and interpolate where the 21 deg timing mark should be.<br /><br />Guarantee you'll burn up the motor if you try and set the max spark advance by ear!! This is not a car engine and by the time you hear enough pinging the engine's probably advanced to the point where it'll be toast.<br /><br />Your ser # is within the range of a 1970 1350 so I'd be careful about jet size.<br /><br />Wondering why you're going to .064 main jets; for a 1970 1150, the stock size for Sea Level is .066 and the book shows .064 for 4000-7000 feet. Are you high altitude?<br /><br />If you have the stock sized main jets already in, I'd recommend you leave them in and see how it runs. You can always change them later, in place, with a modified screwdriver bit.<br /><br />The 1970 1150 started with Ser # 2836019 and the 1350 started with Ser # 2839369, so externally the only way you could tell the diff would be in the carbs.<br /><br />If you look in the carb throat, you'll see a plastic venturi, either black or a creamy-color. In the 1150, this venturi was quite large to restrict airflow (this along with main jet size and smaller reed stops is the only diff between an 1150 and 1350). The 1350 venturi is very small thus flowing more air.<br /><br />So, if you have the large venturi's you've probably got an 1150.<br /><br />Anyway, HTH, be careful don't burn 'er up the first time out! Set up right, she should run well for ya.<br /><br />Cheers.......ed

 

[Clams Canino]

Re: 1970 Mercury 1150 - The story continues (Pictures)

If you run it with too much advance (like setting it for best WOT) and smaller than stock main jets, you WILL guaranteed melt your pistons.<br /><br />-W

 

[MercFan]

Re: 1970 Mercury 1150 - The story continues (Pictures)

Thanx very much Ed and Clams!<br /><br />After all the research into the engine's origins and a strong smell of fuel while running, we came to the conclusion that it was definitaly flooding. We put this down to worn needles and seats. But after looking at various exploded views of the carbs we found the main jets to be off a totally different Merc. They were .076s. Yes I am at high altitude. 4400ft asl, which is how I arrived at my jet size. Standard was specced at .066 and 2 altitude jets of .064 and .062.<br /><br />On the venturi side, they're black, but I don't really have anything to compare it to. I'll take a pic and post it here for your comments please Ed. But if it is indeed a 1350 my jets will be way undersize again! Arg! But lemme do it right!<br /><br />Thanx Clams! That's the info I needed! So best WOT will not be ideal timing! I'll either extrapolate a 21 deg mark, or simply make up a new decal at the office.<br /><br />Thanx very much guys <br /><br />[edit]<br />Well... If the motor is indeed a 1350 the original jets of .076 would be my ideal altitude jets.<br /><br />I'll get that pic of the venturies up asap. <br />And I take that the timing on both these engines is 21 deg BTDC at full advance?

 

[Clams Canino]

Re: 1970 Mercury 1150 - The story continues (Pictures)

If it's a 1350 and you put .066 or .064 in it, it WILL fry. <br /><br />-W

 

[MercFan]

Re: 1970 Mercury 1150 - The story continues (Pictures)

Definitaly! The mixture will be so lean that the mixture will detonate instead of combust!!!

 

[MercFan]

Re: 1970 Mercury 1150 - The story continues (Pictures)

Here's the pics of the venturies. Taken from various angles. Is this engine a 1350 or 1150?<br /><br />

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<br /><br />The project is nearing completion now. And I'm glad that you guys pickup up this potential problem now! If the needles and seats arrive this week, we'll probably put it in the water on Sunday. But I want everything perfect before we take on the open water.

 

[Clams Canino]

Re: 1970 Mercury 1150 - The story continues (Pictures)

Looks 1150 to me assuming the carbs and the block is original. For the year your talking the bloch outta be bare silver unless some yahoo painted it.<br /><br />-W

 

[MercFan]

Re: 1970 Mercury 1150 - The story continues (Pictures)

Thanx Clams!<br />I can't really see the venturies getting any smaller than that, and to be on the safe side I'm gonna put back the .076s till I can get it on big water and run a color tune on it.<br /><br />Don't ask how I'm gonna hang off the back to check combustion color. I'm still working on that <br /><br />I must say the paint looks fairly original, though it is black. Was the 1350 also silver?

 

[emckelvy]

Re: 1970 Mercury 1150 - The story continues (Pictures)

If those are the correct carbs for the motor you've likely got a 1350 and should be running at least .0785 jets. The venturi's are definitely the ones that are used with the 1350. <br /><br />However, they are also used on later model 115's that are ported differently and have larger reed stops than the earlier 1150's. It would help to see a pic of the very bottom of the engine block to help determine for sure what style of block you have.<br /><br />If it's pretty open in the bottom exhaust area, it's the older-style. If it's got split chambers coming off the exhaust plenum, it's later-style.<br /><br />BTW orig 1350 blocks were painted silver as were the 1250's and 1150's. It's possible a factory replacement black block was used or someone just painted the original one black. <br /><br />We'll narrow this bugger down yet, eh?

 

[jimmbo]

Re: 1970 Mercury 1150 - The story continues (Pictures)

It has the two separate fuel pumps that are pre 76. What are the possiblities of it being a 150?

 

[MercFan]

Re: 1970 Mercury 1150 - The story continues (Pictures)

Great great great! Thanx a mil guys!<br /><br />The .076s that I took out of the carb make more sense now. That's the altitude jets for the 1350.<br /><br />I really have a lot of trouble trusting the previous owner/mechanic of the boat. To give you an idea of my biggest shocker. The manual choke lever on the top cowl is supposed to be connected mechanically to the first choke slide. So if you pull the manual choke upwards it will close the choke slides. Easy enough. The guys that had the engine before me, lost that mechanical link. Wanna guess what they put in it's place? An electrical wire that runs from the pole on the choke solenoid!!! And the shroud that bolts down over the powerhead is littered with different bolts. Some metric (Cross threaded into the imperial casing), no 2 bolts are alike!<br /><br />Then as a starting point, I'm gonna assume it's a 1970 1350. The serial number, main jets, venturies and dual fuel pumps all seem to point to this.<br /><br />I'll have a look at the bottom of the engine thanx Ed! And thanx Jimmbo!<br /><br />Jimmbo, the reason why I doubt it being a 150 is the serial number. It falls with the ranges of both the 1970 1150 and 1970 1350.<br /><br />It might actually still be a 1150 and the mechanics that had the engine before me did the old "quick upgrade" to 135hp simply by changing the main jets. I mean Merc is so stupid *Sarcasm* *Sigh*<br /><br />Anyways! I'll take some pics of the bottom cowl around the exhaust area and post 'em!<br /><br />Thanx again for all the advice everybody!

 

[andrewkafp]

Re: 1970 Mercury 1150 - The story continues (Pictures)

The cowling is from a 1982 Merc.

 

[Clams Canino]

Re: 1970 Mercury 1150 - The story continues (Pictures)

Originally posted by MercFan:<br /> .The guys that had the engine before me, lost that mechanical link. Wanna guess what they put in it's place? An electrical wire that runs from the pole on the choke solenoid!!!

Mercury used an electrical type wire from the manual choke plunger to the top choke flapper. Also to go from 1150 to 1350 you had to change the reeds too.<br /><br />-W