[pete500]

hi i have a 1967 mercury 500 50hp 4cyl sn 2118510 im wanting to change the impeller ive tried taking off the lower unit i took off 3 nuts and tried to pry it out but im getting nowhere please help thanks

[elark7]

First never pry, it is too easy to crack that case. You have 2 nuts not yet removed. There is a nut on the front top side, I guess you have it off, two on either side in the middle that cannot be removed fully until the lower unit drops partially, two on the bottom side just forward of the prop, and one hidden bolt underneath the aluminum trim tab. Keep the one front topside on a few turns and remove the two on the sides as far as you can, remove the hidden bolt, and loosen the two on the bottom side. You should see the lower unit start to drop. An extra set of hands or a floor jack help at this point. If not lightly rap , don't get carried away, the casing with a rubber mallet along the edge. If you only get a small seperation and the lower uniot still hangs up use a piece of thin tapered wood, like one for shiming a door, to coax the lower unit apart. I picked up a motor that spent its whole life with the lower unit submerged in water while attached to a boat at the owners private lake and I had to use several shims to get the lower unit to drop. Have patience and you will prevail.

[Chinewalker]

Sort of... Elark is correct that you don't have them all removed, but the location is a bit off. The 500 doesn't have a bolt/stud in front. It does have one more in the rear that involves removing the trim tab (from the top with an allen wrench) and then removing the nut underneath. So the tally is four nuts to remove, plus the one allen bolt to gain access...
- Scott

[pete500]

thanks guys i cant believe how easy that was the tips of the impeller were bent and one was almost gone thank you