Studied the manual and can't figure out if our new to us 3587 has raw water or freshwater engine cooling?
Trying to get a handle on exhaust manifold, riser maintenance requirments. Sounds like a important area to keep up!
Freshwater cooling is different from engine to engine. They all have the block cooled with freshwater, some manifolds are cooled with fresh and some with raw. All risers are raw water cooled. These raw water parts don't last forever and it depends on salinity etc. the important thing to know is that failures are t always externally visible and that if the raw water seeps into the internal parts and engine can be severely damaged. I would discuss with a local mechanics.