Tylerfromig
New member
I have a 2005 Mercury Optimax 225 and I’m trying to track down an oil system issue.
The small engine-mounted reserve oil tank slowly drains while the motor sits, even when the main onboard oil tank is full. The motor sat about 7 months recently and the reserve tank completely emptied.
Before that, I noticed the level would slowly drop over time while sitting. If I take the reserve tank cap off and refill/purge it, the system fills back up and seems normal again.
From what I understand, the reserve tank should stay full because the remote tank feeds it continuously, so I’m assuming I either have:
* a bad check valve,
* an air leak in the oil line,
* or possibly a bad cap/o-ring on the engine tank.
My main question is:
Where is the check valve usually located on these 2005 225 Optimax motors? Is it typically near the engine-mounted tank under the cowling or back near the remote tank in the boat?
Also, has anyone had similar symptoms where the reserve tank drains only while sitting?
The small engine-mounted reserve oil tank slowly drains while the motor sits, even when the main onboard oil tank is full. The motor sat about 7 months recently and the reserve tank completely emptied.
Before that, I noticed the level would slowly drop over time while sitting. If I take the reserve tank cap off and refill/purge it, the system fills back up and seems normal again.
From what I understand, the reserve tank should stay full because the remote tank feeds it continuously, so I’m assuming I either have:
* a bad check valve,
* an air leak in the oil line,
* or possibly a bad cap/o-ring on the engine tank.
My main question is:
Where is the check valve usually located on these 2005 225 Optimax motors? Is it typically near the engine-mounted tank under the cowling or back near the remote tank in the boat?
Also, has anyone had similar symptoms where the reserve tank drains only while sitting?