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1978 Mercury 1150 fried or not ?

C

Chris Yancey

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Ok I also have this posted on iboats. I am a first time boat owner. I bought a 1994 G3 aluminum boat with a 1978 Mercury 1150. I was told it couldn't be started because gas had been left sitting in it. Plus no battery. I pulled the lower end to check the impeller due to it sitting for (one year). I found a major mess. The impeller is melted, small amount of sand around the impeller, and the impeller cover melted in places with heat blisters all over. I'm looking at changing impeller, impeller housing (upper and lower) and all gaskets. What else would need to check ?
Ok have a little info on compression. Still no battery so I grabbed the pull cord and went to pulling
Cylinder 1 105
Cylinder 2 110
Cylinder 3 110
Cylinder 4 105
Cylinder 5 112
Cylinder 6 105
I know using the pull cord isn't the proper way. Just what I had for now.
I had a day off so I got to dig deeper. Here is what I found from bottom to top. Starter bracket broke and missing. Choke took loose or something. Carb baffle / choke plate melted. Merc switch wire cut. Gel on back of switch box melted. Throttle stop missing. I also found 2 metal parts laying in the bottom. I found where they go, but I don't have a clue what they are for.
 

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Not often I agree with dumping an old Merc but in this case with a lot of obvious overheat though the compression numbers wouldn't put me off,it's the melting of the water pump housing and switchbox,a lot of expensive electrical parts needed,that would.It would be a money pit
 
To be honest I don't have 2 grand to sped on a newer motor. What should the compression be ? It was 28* outside when I used the pull cord to test it. Could the numbers go up with a test using a battery ? The damage to the switch box, and wires is due to a fire under the distributor. A guy on iboat forum said most likely from cranking it while it was flooded, or trying to crank it with starting fluid. I payed $200 for the motor.
 
the compression numbers are within 10% of each other so they are not bad..the readings will vary according to the gauge used etc...but unless you have access to a good used parts source then you are going to spend much more than the engine is worth...good luck...
 
Chris Yancey said:
To be honest I don't have 2 grand to sped on a newer motor. What should the compression be ? It was 28* outside when I used the pull cord to test it. Could the numbers go up with a test using a battery ? The damage to the switch box, and wires is due to a fire under the distributor. A guy on iboat forum said most likely from cranking it while it was flooded, or trying to crank it with starting fluid. I payed $200 for the motor.
Click to expand...

That distributor alone if you can find one (if yours is bad) will be north of $1000.00

When NLA is the designation on a part it's time to go for a newer one. You could spend $2K to get it started to find it has a noise.
 
You will need a switch-box http://www.ebay.com/itm/1978-Mercur..._Accessories_Gear&hash=item3f472e2da2&vxp=mtr ,probably a stator if it was electrical http://www.ebay.com/itm/MERCURY-OUT..._Accessories_Gear&hash=item2eddabda7b&vxp=mtr ,plug leads,that distributor looks like it got heated as well http://www.ebay.com/sch/i.html?_odk...nkw=distributor+6cyl&ghostText=&_sacat=111121 ,starter bracket http://www.ebay.com/sch/i.html?_odk...starter+bracket+6cyl&ghostText=&_sacat=111121 .
I reread your post on the idea that it went on fire while cranking while flooded,possible,but I think more likely a leaking carb,fuel running down the leg into the lower unit and a lit cigarette dropping in.:D What does the top of the driveshaft look like,any bluing on it or signs of overheating? Did you pull all the plugs while pulling her over with the rope? Makes it easier to pull over
 
kincrwbr1 I'm honestly wondering what the 2 broke parts are for. I'm hoping I can get by without them. It may have been dropped, and kicked. There is a choke solenoid under the top cover. I just didn't know where to look. As far as the wiring I should be able to rewire it. I've been rewiring cars for years. I know its like comparing apples to oranges but I'm quite sure I can do it. That is the starter bracket, and wiring harness. Thanks very much for the links.
 
I found a used distributor on ebay for $275. It looks to be in good shape. Not being negative but from the price of parts that I've seen.... I could rebuild the engine plus change most other components for under $2000.
 
I'm taking the day off tomorrow so I can start testing. The fire was directly under the distributor. There is honestly no telling how the fire started. The drive shaft looks good from top to bottom. Yes I did pull all the plugs. I've done compression test's on many many cars.
 
Untill you can do a accurate compression test don't buy anything. From you other posts on different site jump the starter with cable and get a reading. If motor got hot it can have scuffed cylinders and still have compression from rope testing
 
Should I oil the cylinders before anymore testing ? It has been sitting dry for 2 years or sure. I would have to service the fuel system to get fuel to it.
 
All I'm going to do until I get a starter bracket is another compression test. What did you notice on the lower engine cover that would affect the shift linkage ? I looked on craigslist and they are about $700 to $900 for most parts motors. No mercs though. I didn't find any oil in the gear box but all the gears look good. all sharp edged and no sign of running dry.
 
Ok I go t d some testing. Ignition (key) (good), wiring harness checked out other than the melted wire. Starter solenoid (good), starter (good), power to switch box (good) coil (good) Coil wire jumps a nice blue spark about 3/4" long.
 
\qRe: 1978 Mercury 1150 fried or not ?

All I can see is the side of the piston. Can't see into the cylinder to look at the cylinder walls. Went and bought a bore scope. All the cylinder walls are smooth, no scratches, and shinny as a mirror.
 
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