Logo
FULL SITE MENU

Help on 1976 4 cy 3.0L 140 HP Replacement

S

spartyfan1972

New member
Can I go from a 1976 4 cy 3.0L 140 HP OMC, to a 1983 4 cy 2.5L 120HP OMC? The current engine is smoked and I found a great replacement. Just not sure if I can drop it in? Not concerned about the drop in HP, just want to fish and cruz with the kids.
 
remove the motor and leave the bell housing in place without removing the drive.

Disconnect all the wires and cables to the motor. Mark what wire goes where. Remove the 4 screws and one thru bolt for the main ground that holds the motor to the bell housing.

Remove the 5 screws that hold on the flywheel cover. Remove the flywheel cover.

Crank the bow down so you can lower the drive all the way and place a flat piece of wood under the skeg and then crank the bow up till the skeg touch's the wood.

Remove the 2 large bolts that are actually screws that hold the front motor mount to the stringers.

Now with a strap around the elbow and one around the crank pulley or the lifting eye if you have one lift the motor enough for you to be able to sldie the motor forward 6 " and then straight up.

Remove the coupler from the old motor and install onto the new motor. Grease the splines on the shaft. Change over the front mount.

Paint the new motor everywhere 3-4 times and drop in the motor and slide it back onto the drive shaft and re-install everything you removed before.

With a stringer drive it is the way to go.
 
You didn't mention what 140 HP motor you are putting in. You cannot use a fork lift nor a passenger car motor. They won't work. If you are referring to the 153 cu in, yes it's a direct swap and you should not have anyo problems except those that you create. I suggest you flush 'all' water passages before installation. Also, check your old manifold gasket with the new engine head as that is key to verify they match. During swap, support your out drive so as to not damage it or your hull.
 
Back
Top