1988 80 HP 3 cylinder O/B - lower unit stuck

[kaempfe]

I am trying to replace the impeller on my 1988 80 HP 3 cylinder O/B. I took out the (5) bolts and the 2 back ones (nearest boat) were a little tough to get out. I put it in forward per my local mechanic so everything stay aligned but I read online that neutral was needed to it doesn't bind to the splines. I can seem to get the lower uinit to break free. I'll get a rubber mallet tomorrow but I don't want to force it when I'm not sure what Im doing.

Any suggestions?

Thanks
Scott

 

[Texasmark]

Re: 1988 80 HP 3 cylinder O/B - lower unit stuck

Your setup should be similar to my 1990 dated service manual. Manual shows 2 screws per side just above the anti vent plate and a nut at the rear , accessible from beneath the anti vent plate immediately forward of the trim tab. (5 fastners as you mentioned you removed)

It recommends F gear, tilt all the way up. Then you have 2 splines and one copper tube to separate from the powerhead in addition to overcoming any corrosion at the interface of the LU and mid section. There are 2 alignment pins (1 fore and 1 aft) so the lower unit will not turn left or right till you separate it enough to clear them.....you don't want to do that anyway. A good dose of a quality penetrating oil will help on the interface mating surfaces.

The anti vent plate is not made to be banged on and if you hammer on it you can find yourself with part of it breaking off. I'd take wooden 2x4 and place it above the prop and beat on that if you have to beat on something. As soon as you get a crack at the interface, I'd use a screwdriver and tapping hammer and start working around it trying to keep the break even as it comes down.

HTH

Mark

 

[kjspylite]

Re: 1988 80 HP 3 cylinder O/B - lower unit stuck

I had the same problem when taking my lower unit off the first time. I think I was trying to be too easy with it and just tried to pull it down with my hands. I used a block of wood like Mark suggested and tapped it off with a hammer. Worked great!

 

[kaempfe]

Re: 1988 80 HP 3 cylinder O/B - lower unit stuck

I was not aware of the copper tubing and splines. I will take a look tonight.

Any recommendations on the penetraing oil? Is there one that works best for Marine corrosion?

Optimistically looking forward....
When putting everything back together...I saw in teh you tube posting to use some RTV near the exhaust vent. Does your manual say anything about that?

When inserting the impeller into the housing...A you tube video said to slide the impeller in while turning counterclockwise because this part of housing faces down and will then be in alignement with the clockwise turning prop. Does you manual say the same?

I bought a manual but...maybe because of the range of years is addresses...is too vague for my liking.

Thanks a ton!

 

[kaempfe]

Re: 1988 80 HP 3 cylinder O/B - lower unit stuck

Well...the good news is that I got the lower unit to come free. Once it started to move it was easy. The bad news is that a broke off a section of the fin on the lower unit near the front (opposite of prop). It is about 3.5" long and about 1/2" wide. There is a bolt hole in the proximity but it doesn't appear to have a crack anywhere else.

1. Is this going to be a problem? Can I run it anyway? What is the danger?
2. Is there a way to repair it?

Thanks

 

[kaempfe]

Re: 1988 80 HP 3 cylinder O/B - lower unit stuck

Here some pics of the damage. I appreciate the feedback.