Impellar replacement-lots of questions

[brielly]

This is the 1st time I'm doing an impellar and a few things have me stumped. I got the lower unit off but the plastic water tube?? looks very strange to me. It doesn't seem to be held on by much (its loose and wobbles around) and it is off center with the metal tube. In the manual it looks like it should have come down with the impellar cover and the rest of the lower unit but instead it is still on the upper unit. Please see picture. Should it be this way or is something very wrong?

My other question is in regards to reinstalling the lower unit. The clymer manual says shift the gear housing into forward gear. How do I do this and where is the location of the guide block pin?

They also mention gm silicone sealer. Can I substitute one of the permatex sealers? Any help would be appreciated as I'd love to get this boat in the water one of these days.

 

[kennyboater]

Re: Impellar replacement-lots of questions

not sure what motor (size and hp) that you are working on, but on my 1985 25hp the whole water tube does not come down (off) with the lower unit. just about on inch long piece of rubber that connects the water pump to the water tube.

i did not use any sealer when reinstalling, maybe i should have...my seolic manual did not say anything about it.

 

[brielly]

Re: Impellar replacement-lots of questions

Its a 1991 135 hp v6. My main concern is why the plasic tube is off center from the metal tube its attached to. Maybe it should be that way but it just doesn't look right to me

 

[LORDY611]

Re: Impellar replacement-lots of questions

If I recall correctly, on my 40 it was one of the last and most tricky things to do: align the hanging tube with the one in the lower unit.

 

[DRIFTER_016]

Re: Impellar replacement-lots of questions

My 1991 90HP 3 cyl has the short rubber coupler as well. remove it and place it on the output connection on the water pump upper housing.
You should have put it in forward gear before dropping the bottom end as it is then just a matter of turning the prop to line up the splines in the output shaft.
Now there are 2 ways to line it up 1/ shift your controls into forward gear and on the LU there should be a small splined shaft that is the shifter shaft. Turn it clockwise (I think) with a pair of pliers until it engages forward gear.
And reinstall.
2/ remove spark plugs and while one person holds the LU in place have a second person slowly turn the flywheel until the splines line up and slide into place.

It's also easier to reinstall the LU if the motor is trimmed all the way up.

When you are replacing your upper waterpump housing after installing the new impeller make sure you turn the output shaft clockwise so that the impeller vanes are seated in the correct direction.

One more thing: pick up a Mercury Repair Manual for your motor they are by far the best. It was my first purchase when I bought my boat and is invaluable.