Buckeye Boater
Active Member
Running a Mercury 5.0 MPI with an Alpha One outdrive. Spent about six hours on the water today running at various speeds, anchored at the beach, etc. After swimming for an hour or so, headed back out on the lake for one more run before heading back to the ramp to pull the boat out and head home. On the final run, boat traffic had cleared somewhat and we finally had some smooth water. We typically run about 3000-3100 RPM's. With the smooth, clear water, I bumped it up to about 4200 RPM's for at most two minutes before heading into the no wake zone. While running, at higher RPM's and idle, continued to monitor gauges - temp and oil pressure remained normal. After 15-20 minute run at idle through no wake zone, we loaded the boat on the trailer and pulled her out and cleaned her up for the ride home.
This is when I noticed a brownish residue on the transom, starboard side only, next to bell housing, from the waterline to just above the plug, about 6 - 8 inches wide. It wiped right off. Did not have any odor (i.e., fuel, oil). When we had returned to the ramp, there was no oil/fuel sheen on the water as I checked to make sure the outdrive was straight and raised. Also checked the bilge - was clean/dry as it was to start the day.
Any ideas as to the source of the residue?
This is when I noticed a brownish residue on the transom, starboard side only, next to bell housing, from the waterline to just above the plug, about 6 - 8 inches wide. It wiped right off. Did not have any odor (i.e., fuel, oil). When we had returned to the ramp, there was no oil/fuel sheen on the water as I checked to make sure the outdrive was straight and raised. Also checked the bilge - was clean/dry as it was to start the day.
Any ideas as to the source of the residue?
