81 Johnson 7.5 Cyl Head torque specs.

[mik0068]

Im curious what the torque is on the head bolts. The motor is a 81, 7.5 Johnson. I've just rebuilt the carb,new tstat,throttle cable,plugs,water pump rebuild kit & imp installed, changed lower unit lube...SO, I hope this thing runs nice. When I got it, it had spark, 90 or so compression in both cyls., but did not run. By the way,this looks like a great site! Hope to learn alot...Thanks

 

[cajuncook1]

Re: 81 Johnson 7.5 Cyl Head torque specs.

Per manual specs 144 to 168 inch pounds (notice I stated inch pounds and not foot pounds)

You will tighten the cylinder head 3 times

1st pass will be at 50% torque

2nd pass will be at 100% torque.

3rd Run the motor and get it nice and warmed up and then make your third pass. The third pass is to insure torque value after the head warm up and does not cause loss of seal due to heat expansion.

Use the torque sequence as displayed below. It ensures good even seating and a good seal. These are not your exact cylinder head, but gives you the idea of proper sequencing.

click on image for better display.