Merc 4.5 L/U 2 questions - PICS

[Grant Brown]

1984 S/N 7216798.
I need to replace the water pump impeller. I am having trouble getting the lower unit off. I have loosened the 9/16" nut off the leading edge and removed the 1/2" nut off the underside of the cav plate. Feels like it's hanging up on something or I missed a fastener. The l/u is separating at the aft side only.
1) What am I missing?

Also, the water pickup screen doesn't want to come off. Its held on by the 1/2" nut at one end and the other end looks like it has a screw holding it but it's so corroded I can't tell what it is.
2) What type of fastener holds the screen on?
http://www.grantbrown.ca/motor.jpg
http://www.grantbrown.ca/Img_2369.jpg
http://www.grantbrown.ca/Img_2368.jpg
http://www.grantbrown.ca/Img_2367.jpg

 

[Chinewalker]

Re: Merc 4.5 L/U 2 questions - PICS

The screen doesn't generally need to come off. The foreward end is usually riveted in place.

I'm pretty sure those two studs are the only ones holding that unit on. The forward stud may be corroded into the mid-housing a bit, keeping it from dropping down. Gentle persuasion with a rubber mallet, heat from a propane torch, penetrating oil, etc. may loosen things up.

- Scott

 

[Grant Brown]

Re: Merc 4.5 L/U

Re: Merc 4.5 L/U

Thanks, that worked great. I wasn't sure if I found all the bolts or not. I gave it a good shot of penetrating oil last night and few sharp whacks with a hammer and block of wood. Lots of salt in there.

Grant