Hey all,
The lower unit on my 2002 15hp
Mercury two stroke has seen better days. It's not dead yet, but I need some help with it.
Because of a stripped screw and mangled screw hole a couple of years back, I had to glue (with Marine-tex) a small
aluminum plate over the
oil vent hole and tap a new screw hole in that. It worked fine for a couple of years, but when I had the
water pump replaced last month, the guys at the shop apparently over-tightened it because the threads stripped out and it leaked. I
solved this problem by re-tapping the threads in the
aluminum plate one size larger and getting the appropriate bolt for it. I wrapped the screw threads in teflon tape, put red RTV
gasket maker under the bolt
head and tightened it down. Then I put more
gasket maker over the top of the bolt
head just in case.
This looked and felt completely leak-proof, and for about a month it worked great. Then I noticed that the hole was starting to ooze
gear oil again, this time just a tiny tiny bit. I was able to tighten the bolt another half turn, and now the leak has stopped again. Maybe the vibrations had loosened it up a bit or the gasket maker shrunk when it hardened.
Obviously I need to drain, inspect and replace the oil. But how can I avoid going through this process yet again? I am hesitant to tighten the bolt too much, lest I break the threads in the aluminum plate, but if I don't tighten it enough it will leak for sure. Is the teflon tape helping or should I use something else? Is there a better
sealant to use? Thread locker perhaps? If so, which one? (please be specific)
Any
advice is appreciated.
Thanks,
Jack