1989 Force Bolt Holes on Lower Unit...

[mikehayes]

I finally bought my first boat last summer (YEAH!) It's a lightly used 1989 Cobra with a 50hp Force Motor. I ran into a problem at the end of last summer where it would not plane and seemed to be revving up quite a bit, and did not show any noticeable water shooting out of the holes at the top of the engine. Your webpage had some topics of similar concerns and suggested changing out the impeller and water pump. I did this as well as changed out the lower unit oil and the two sparkplugs. When I took off the lower unit, I noticed that one of the bolt holes had an offset hole that ties into the threaded part of the hole which does not get covered by the bolt when inserted and tightened. It seemed as if water would enter the lower unit area. I used anti-seize on the bolt threads but I knew this one hole was vulnerable to water seeping in. After getting everything together, I put a large container under the prop and fired it up. It did fine, and after warming up it was spitting out water from the holes in the top (EXCELLENT). Anyway, a few days later I was working on the boat, and turned the steering wheal and heard water dripping in my garage. I looked at the engine, and noticed that water was leaking out of this offset hole around the lower unit bolthole. Is this normal, what's it for and if not, what should I do?<br /><br />Thanks,<br />Mike

 

[roscoe]

Re: 1989 Force Bolt Holes on Lower Unit...

Welcome to iboats.<br />If water is not getting into the lower unit lube, then you are ok.<br /><br />I believe this "drain hole" is used to drain water that is left in the mid section, above the lower unit.<br /><br /><br />As for the engine revving high, but no power or speed:<br /><br />Sounds like the prop hub has "spun".<br /><br />There is a rubber bushing that is pressed between the inner and outer parts of the prop. When it gets old/worn, or you strike a rock, the rubber loses its bond.<br /><br />You can test your prop.<br />Remove the prop.<br />Scribe a line, or use nail polish or permanent marker.<br />Line must go from outer portion of prop, across the end to the inner part.<br />Install prop, test drive, accellerate hard several times and try to run at speed.<br /><br />Now remove the prop and inspect the line.<br />If the line is no longer lined up across both parts, then the hub has spun.<br /><br />The hub can be replaced at a prop shop, or so boat shops.