1971 Merc 1350 Problems

[werty32]

Hi all, ive got a mercury 1350, 1971 model by the looks of things, i've started the motor briefly, but when i turned the tap on (water flush) the motor wouldnt start and im getting water drops on the ends of the spark plugs, I'm about to pull the block off the middle section and start stripping the water jacket and exhaust jacket off, any other suggestions i should of what i should look for? And if anyone knows of where i can get parts i might need for this motor (other than oldmercs.com) dont hessitate to let me know!

Just to add, ive got 150+ psi compression in 5 cylinders, #3 is a bit lower, about 120/110 psi....

Might the exhaust plate be the cause of my problems? i havent looked under the exhaust water jacket cover yet....

 

[Chris1956]

Re: 1971 Merc 1350 Problems

Water can get into that motor's cylinders via a hole in the exhaust baffle, a hole in the inner exhaust cover, via leaking lower crankshaft seals or a crack in the block, which would be rare.

Be careful removing the exhaust cover bolts, as they have a tendency to break. Use some heat, penetrating oil and a hand impact driver on them, and pray a lot

 

[fishdog4449]

Re: 1971 Merc 1350 Problems

I'll second that, most likely the exhaust baffle(s) or gaskets. Had the same thing happen to mine (1150). It's not a hard repair, but you do have to pull the powerhead. The guys here told me to remove the powerhead first, I thought I could work around the lower cowl and didn't listen. I got all except the bottom two bolts out, and ended up having to remove the powerhead anyway.

While you've got the powerhead off, check the number 3 piston and walls for scoring. On the straight sixes, number 3 or 1 usually goes first.


150+ is great. These motors are bulletproof and will last forever if you replace that impeller every season, run 93 octane, and prop it right.

 

[werty32]

Re: 1971 Merc 1350 Problems

Thanks for the help guys! I'll take some photo's of the internal's as i pull it apart for you to have a look at...

When i bought the motor 12 months ago, it was sold to me as a motor that wouldnt pump water, The first thing i did was Pull the leg off the mid section, Pulled the Power head off, Put a new water pump in the leg, got the oil changed and the leg pressure tested, I then put the motor back together on the back of the boat... starting with the mid-section/trim first, I wired that up from scratch, I then put the leg on, and then after that i put the power head back on...

After realizing the state of the wiring on the side of the engine, i started from the stator coil back, and rewired the motor all the way to the ignition switch... Which got it all started (untill i put water on it)

While ive got the block off, im going to get some carb rebuild kits (if i can get them) and the fuel pump rebuild kits/gaskets... to make sure their all good as the motor has sat idle for quite a few years by the sounds of things, and the exhaust water jacket cover looks like it has been taken off at some point in time, because there is silicone glue around it.... I'll let you know how much trouble i have getting the inner baffle off i can tell that's going to be tricky.... All nuts and bolts im taking off that aren't stainless im going to replace with stainless...

 

[werty32]

Re: 1971 Merc 1350 Problems

Ok i got the power head off! i took the head water jacket cover and exhaust jacket cover off... I think the water leak im getting is through the lower crank seal, THERE WAS NOTHING LEFT OF IT except a metal ring that fit over the driveshaft... heh.. Anyways there is a fair bit of corrosion build up in the water jacket but the baffle and internal parts of the exhaust look 99.9%...

When i popped the bottom crankshaft seal out there was milky gunk everwhere, and the milkyness was predominantly at the bottom of the block, nothing bad at the top end or middle... The pistons look a little scored from what i can see of them, so i might look at boring it out and putting some over sized pistons in once i figure out the size the bore is currently at...

Should i bother splitting the block in half when i wash all the muck out? or just leave the lower crank seal off, and take the carbies off, and give it a good wash out with some petrol? I probably wont bother with the rebuild at the moment... once i get this baby going ill probably use it for 12 months then sell it and upgrade

 

[Chris1956]

Re: 1971 Merc 1350 Problems

Werty, There should be room for three crank seals in the lower end cap. Three is what I recommend. Check the lower main bearing. The water may have damaged it. Inspect the lower reed valves, thru the end cap hole, if you can. See if there is corrosion on the reed petals or stops. If so, you need to rip it down, and clean it up.

Replace the oring seal around the end cap. If there is a shim on the lower end cap (not usually, but who knows at this point), be sure and reinstall it. Check the crank end for grooving and roughness that would tear the crank seals and if rough, clean it up. I think it will be hard not to have to open the crankcase, but it may be possible.

 

[mthieme]

Re: 1971 Merc 1350 Problems

Agree with others on the bolts.
You can almost count on some drilling and tapping.
I removed a powerhead on a 35 last year - 3/4 bolts were obstinate.
That's a cool motor. You don't see too many 135's; they only made it two years.

 

[werty32]

Re: 1971 Merc 1350 Problems

http://www.facebook.com/photo.php?pid=5740071&id=600590563


Thats my boat and motor! a 17 Foot 1977 Camero Farina with the merc 1350 on the back.... Ive got a windscreen on order, and once i get the motor working im going to trim the interior... Ive re-sprayed the top half of the boat, just got to do from the bumper strip down and under the boat....