aquarius23
New member
Hello,
I have a NS40D2 ser# 47114 that is leaking oil from under the powerhead from where the upper pivot is. It runs under the splash guard and down the front of the driveshaft housing. After a 4 hour hour run it will leak about 15 mls or 0.5 oz of oil. Mostly it will not show up the same day but the day after.
The powerhead was rebuilt about 20 months ago. It has leaked oil from day one. Because of covid I just covered the boat up until 8 weeks ago. I have been trying to find the problem ever since. Things I have done so far are.
Removed the powerhead to check the seals and o-ring in the lower crankshaft head. All looked good but I replaced seals and o-ring with new ones.
Removed the intake manifold to check the gasket. No problem found. Replaced the gasket and reed valves.
Replaced all o-rings , gasket, floats. float needles in the carbs.
Removed the entire auto oil system. Tank, filter, mixing valve, all oil lines and removed the oil pump removed the oil pump drive shaft then reinstalled the oil pump to cover the hole. Ran the motor on 50 to 1 mix. Seemed to leak more.
I checked all the control rod lengths, checked timing, checked oil pump output. Checked mixing valve for proper pressure. Checked link and sync. All good per factory service manual.
All fuel and oil lines were replaced during rebuild and again within the last 8 weeks.
The motor runs great. Smooth idle good power. Compression 132 to 135 all cylinders. All spark plugs are a medium brown.
I am out of ideas. Please help. Thank You
I have a NS40D2 ser# 47114 that is leaking oil from under the powerhead from where the upper pivot is. It runs under the splash guard and down the front of the driveshaft housing. After a 4 hour hour run it will leak about 15 mls or 0.5 oz of oil. Mostly it will not show up the same day but the day after.
The powerhead was rebuilt about 20 months ago. It has leaked oil from day one. Because of covid I just covered the boat up until 8 weeks ago. I have been trying to find the problem ever since. Things I have done so far are.
Removed the powerhead to check the seals and o-ring in the lower crankshaft head. All looked good but I replaced seals and o-ring with new ones.
Removed the intake manifold to check the gasket. No problem found. Replaced the gasket and reed valves.
Replaced all o-rings , gasket, floats. float needles in the carbs.
Removed the entire auto oil system. Tank, filter, mixing valve, all oil lines and removed the oil pump removed the oil pump drive shaft then reinstalled the oil pump to cover the hole. Ran the motor on 50 to 1 mix. Seemed to leak more.
I checked all the control rod lengths, checked timing, checked oil pump output. Checked mixing valve for proper pressure. Checked link and sync. All good per factory service manual.
All fuel and oil lines were replaced during rebuild and again within the last 8 weeks.
The motor runs great. Smooth idle good power. Compression 132 to 135 all cylinders. All spark plugs are a medium brown.
I am out of ideas. Please help. Thank You