torque specifications for 1983 50 hp mercury outboard for water jacket gasket

[boatman2013]

hello can anyone please tell me the torque specs for the bolts on a 1983 50 hp mercury outboard for the water jacket cylinder gasket? thank you very much.

 

[Texasmark]

Re: torque specifications for 1983 50 hp mercury outboard for water jacket gasket

Just www for torque specs for SAE bolts. Numbers can be for dirty, clean, or lubed threads. It matters. I think those bolts are 5/16 and for clean dry threads 20 ft-lbs is roughly the rating. That's for a grade 5 (3 marks on the head) but marine engines use SS which are much higher rating. The alum threads in the block will shear off and threads strip before you break the bolt from over torqueing.

You should run a chaser through the block threads and blow them out to clean them up. Run the bolt threads over a motorized wire brush....like is on the same shaft with your grinder. Then a Blue Locktite on the threads which will keep the bolts tight and lube up the interface.

What I do is forget the torque spec. I get a socket with my hand midway on it and do the X pattern starting from the center and working out in both directions just snugging things up. Then a second trip and then a third trip where I put my max whoopie which is just good and tight with my hand where I said. You can do a lot of snugging up a little more, on an individual basis IF a leak should occur before you spend time and go through the laborous process of tearing the whole shebang apart trying to dig out stripped threads and drilling and taping for a helical coil.

I don't put that gasket on dry. I coat both sides with a thin coating of blue RTV, let it air cure for 5 minutes or so and once buttoned up, let it sit up for a couple of days before using.

If you ever stripped threads in an aluminum block (I have) it is a very, very, sick feeling and once you do it, you can't go back. What's done is done.

HTH,
Mark

 

[carholme]

Re: torque specifications for 1983 50 hp mercury outboard for water jacket gasket

Small Engine Repair Reference Center Home: MERCURY - MERCURY FOUR-CYLINDER MODELS (1969-1989).

Download soonest to your computer as the link is short lived. Torque specs on page 267/268.

Gerry

 

[carholme]

Re: torque specifications for 1983 50 hp mercury outboard for water jacket gasket

TIGHTENING TORQUES
Connecting Rod 180 in.-lbs. (20.3 N-m)

Crankcase Screws:
Models 650 & 800 (Prior to 1973) 150 in.-lbs. (16.9 N-m)
All Other Models 200 in.-lbs. (22.6 N-m)

Cylinder Cover:
Models 45, 50 & 500 70 in.-lbs. (7.9 N-m)
Models 650 & 800 (Prior to 1973) 100 in.-lbs. (11.3N-m)
Models 800 (After 1972), 850, 80 & 75 85 in.-lbs. (9.6 N-m)

Exhaust Cover:
Models 45, 50 & 500 200 in.-lbs. (22.6 N-m)
Models 650 & 800 (Prior to 1973) 150 in.-lbs. (16.9 N-m)
Models 800 (After 1972), 850,80 & 75 250 in.-lbs. 250 in.-lbs. (28.2 N-m)

TIGHTENING TORQUES CONT.

Flywheel:
Models 800 (After 1972), 850,80&75 100 ft.-lbs. (136 N-m)
All Other Models 65 ft.-lbs. (88.4 N-m)

Reed Screws:
Models 45, 50 & 500 30 in.-lbs. (3.4 N-m)
Models 650 & 800 (Prior to 1973) 35 in.-lbs.(3.9 N-m)

Models 800 (After 1972), 850,80&75 25 in.-lbs. (2.8 N-m)

Spark Plugs 240 in.-lbs. (27.1 N-m)

Transfer Port Covers:
Models 800 (After 1972), 850,80&75 85 in.-lbs (9.6 N-m)
All Other Models .60 in.-lbs. (6.8 N-m)

 

[boatman2013]

Re: torque specifications for 1983 50 hp mercury outboard for water jacket gasket

Thanks for the replied everyone. Gasket is on and no leaks. thanks again.