MerCruiser Alpha One Service Bulletin

TO: SERVICE MANAGER
PARTS MANAGER
Alpha One Generation II Over Heat
Models
ALL

Situation

Over heat condition on Alpha One Generation II at 3000 RPM and above.

Trouble Shooting

Connect a clear plastic hose from the thermostat housing to the bottom of the exhaust manifold
on the starboard side of the engine. Take the boat out and water test it. Watch the clear hose for
air bubbles at around 3000 rpm and above. If the hose starts to fill with air bubbles, observe it until
it is about two thirds air bubbles and one third water. Watch the temperature gauge. It should begin
to show an increase in temperature. If no air bubbles appear and the water in the hose stays solid
with no air, you need to check other parts of the engine or transom.

Correction

Remove the drive from the boat, and separate the gear housing from the drive shaft housing. Re-
move the water pump top, impeller, gaskets and face plate. Reinstall with new gaskets and (impeller
if required) using the following steps.
1. Coat the first gasket with Perfect Seal on the side that goes against the gear housing.
2. Place the face plate on top of the base gasket.
3. Place the top gasket on top of the face plate.
Printed in U.S.A.
service bulletin
TECHNICIANS
- 1 -
No. 95-13
70720
95-13 895