My 1999 Honda 9.9 OB worked great for the last cruse, but, after being dry-docked for 2 weeks it is overheating (I hauled out the boat for bottom job plus an enamel job on the rest of the boat) and knocking. Anyone know the best place to get the book on this motor? I'm thinking the impeller may need replacing, any other opinions?
Motor overheating
- Thread starter Donald6441
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I had a hot Honda once!
Is water coming out of the small discharge hose at the back of the motor? Is the strainer on the water inlet in the leg of the motor clear? I had a spider set up house keeping in the discharge once, used a flexable bit of wire to clear the hose, end of problem. Tom s/v GAIA
Is water coming out of the small discharge hose at the back of the motor? Is the strainer on the water inlet in the leg of the motor clear? I had a spider set up house keeping in the discharge once, used a flexable bit of wire to clear the hose, end of problem. Tom s/v GAIA
I sprayed the motor lower end with anti-foul
about 4 layers, the inlets look clear. Ill check the discharge...
about 4 layers, the inlets look clear. Ill check the discharge...
well, checked it out better today
The thermostat was frozen, so I pulled that out. The motor is still overheating, lasting a bit longer but still overheating. I ordered the service manual for the motor so hopefully I can figure this out quickly. Im going to go ahead and order an impeller and new thermo. The hoses all look good, so I don't think any hoses are the cause. I suspect the thermo froze and caused the pump to mess up due to not enough water coming into it.
The thermostat was frozen, so I pulled that out. The motor is still overheating, lasting a bit longer but still overheating. I ordered the service manual for the motor so hopefully I can figure this out quickly. Im going to go ahead and order an impeller and new thermo. The hoses all look good, so I don't think any hoses are the cause. I suspect the thermo froze and caused the pump to mess up due to not enough water coming into it.
If the thermostat was stuck
You could have cracked the head or blown a gasket. We did this about 25 years ago on a Johnson and it would still start and run fine until it heated, then overheated.
You could have cracked the head or blown a gasket. We did this about 25 years ago on a Johnson and it would still start and run fine until it heated, then overheated.
Hot motor
A 99 model motor is probably past due for a new impeller. Most people I know change them every other year. Even if not used a lot, they can take a set and not pump enough to cool. It's a pretty east job if you get a good manual.
A 99 model motor is probably past due for a new impeller. Most people I know change them every other year. Even if not used a lot, they can take a set and not pump enough to cool. It's a pretty east job if you get a good manual.
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