Merc impeller?

[Gordie]

I have a 1987 classic 50/45 hp and I would like to change the impeller on it I have changed them out on yamaha'a and a couple of older evernudes but never on this one is it just the 4 bolt that hold the lower unit on or is it connected any other place.

Thanks for the info

[boatfixer]

There should be another bolt under the trim tab

[Gordie]

thier are two on the sides and one onder the trim tab and one in front of the trim tab but the lower untit comes down about a 1/4 inch and stops seem free on trim tab side but the front of the unit feels like something else is holding it. I really dont want to pry it off or use a BFH

[boatfixer]

IS it separating in the front? Older mercs had another stud at the leading edge, I dont think your does tho. If the whole thing is separating then all the nuts and bolts are removed. I use a plastic dead blow to GENTLY, OH SO GENTLY, tap on any beefy part of the housing. Dont tap on the anti-ventilation plate. I'm thinking in your case, the drive shaft splines are holding you up.

[CAMAN]

I have the same motor and mine did the same thing first time I tried taking it off. It should just be the driveshaft splines and copper waterline holding it from here.

What I did was put the motor in vertical position. Put a couple blocks of wood under the skeg so if it drops it doesn't damage your concrete floors. I was also afraid of hitting with a hammer so I used its own weight to break it loose. I would lift up and quickly push it down creating a slide hammer effect. It will eventually break loose and drop so if the drop is going to be more than an inch or so put a ratchet strap or something around the motor and lower unit to catch it.

Have fun! IMO, putting that dang water tube back correctly into place during assembly is a PITA and the most difficult part of the job. Also be sure to keep track of the drive key that goes between the water pump and drive shaft, they tend to want to pop out and run away during disassembly.

[Gordie]

Thanks guys I will be giving it a try this week

[MinnesotaMike]

I just took my lower unit out of my 1980' Merc 50hp. Mine slid out nice and easy once I was told there was a nut under the skag.

Keep an eye on your drive shaft, mine had a hard plastic and soft rubber slide on the spines. I only noticed it because I had to look up the lower unit to see where the water pipe went back in. They got hung up in the motor and came off.

Good luck,

Mike