Mercury o-rings needed for impeller replacement

[CaptanMason]

Hello,<br /><br /> <br /><br />I undertook the replacement of my impeller per some instructions “Lets Replace that Water Pump”. There were two things that I am questioning and could really use some clarification.<br /><br /> <br /><br />Older Mercury 850, 85hp, two stroke, four cylinder, short shaft...no serial number could be located so unsure of year but about 80ish.<br /><br /> <br />Instructions read:<br />Stop and locate the tiny seal (looks like a little rubber washer) that seals the oil passage between upper and lower units. It may still be on top-center-starrboard side of lower/unit. <br /> <br /><br />I was unable to locate this little rubber washer or any place that it could have gone in the first place. Could it be that my particular model does not have this set-up?<br /><br /> <br />Instructions read:<br />Slide rubber seal down drive-shaft and replace top o-ring. <br />Again, this "top O-ring" was not removed. Is this just an O-ring that slides over the *** at the top of the drive shaft?<br /><br /> <br /><br />Would appreciate any help,<br /><br /> <br /><br />CaptanMason

 

[AMD Rules]

Re: Mercury o-rings needed for impeller replacement

1000 words = one picture<br /><br />Are you only replacing the impeller, or the complete upper and lower water pump housing?<br /><br />Did you look for a serial number on the block somewhere? Its often stamped in a few places. Should be a 7 digit number. <br /><br />Some drive shafts don't have the upper o-ring. If you dont see an o-ring groove...chances are yours does not. The small 3/16" diameter '***' is often spring loaded to pre-load the crank shaft. Either way it does not have an o-ring around it.<br /><br />I'm not familair with that o-ring on the center-starboard side of the lower unit. Are these generic instructions that may pertain to an outdrive for an i/o by chance?

 

[CaptanMason]

Re: Mercury o-rings needed for impeller replacement

I never did find what they were talking about,

I did replace the impeller, all gaskets and o-rings (that I could find), and the wear plate. Greesed it up and put it back together and all seems to be working great. The test will be in two weeks when I beat her up in PC FL as I have done so many times in the past.

The instructions were found on a site called www.brokeboats.com. They were not bad instructions and I am somewhat above moderately confident.

We'll see,

 

[Chris1956]

Re: Mercury o-rings needed for impeller replacement

Captan Mason, It sounds like you were using the waterpump replacement instructions from a Mercruiser Alpha 1 sterndrive. They are the same, except your outboard does not have an upper gearcase, so you do not need that seal (no where to put it), and there is probably no o-ring on the upper driveshaft. That Oring seals the upper gearcase on the Alpha 1 unit. Don't fret, since the Outboards and the Alpha 1 Gen I units share the same waterpump kits. You simply leave out some o rings and gaskets.