Mercury 200 OptiMax Jet Drive Service Manual page 348

1 - Inlet cooling water from jet pump
2 - Water inlet from flushing connection
3 - Water flow from adapter to powerhead
4 - Water fills center of powerhead, flows over exhaust runners, then to cylinder jackets
5 - Water pressure sensor
6 - Cooling water fills cylinder jackets, then flows to cylinder head
7 - Majority of water flows down cylinder head. Cylinder head cover has been removed from head for illustration. It is normally
part of head casting.
8 - Small amount of water flows out top of head to water bypass. The thermostats are removed on the jet drive powerhead.
9 - Water bypass ‑ discharged outside of boat
10 - Water flows from bottom of cylinder head through passage in cylinder block to adapter plate
11 - Water flows from block through adapter plate, cooling exhaust passages in adapter
12 - Water flows from adapter to expansion chamber water jacket
13 - Cooling water from expansion chamber is emptied back into adapter plate
14 - Cooling water from adapter plate is exhausted through the jet tunnel
Compressor and Fuel Cooling Circuit
15 - Fitting with strainer
16 - Incoming cooling water is directed to fuel rail
17 - Water flows through fuel rail (port) to air compressor
18 - Air compressor
19 - Water flows from air compressor to expansion chamber exhaust pipes
20 - Cooling water for exhaust tubes is discharged with exhaust
90-8M0050731 MAY 2011
Powerhead and Exhaust Cooling Circuit
Cooling
Page 4B-9