Logo
FULL SITE MENU

1977 98 HP Mercury fuel leak

H

hayesd

New member
"My 1977 9.8 hp is running bet

"My 1977 9.8 hp is running better than it ever has, however there is a lot fuel leaking into the water. From what I can tell the fuel lines seem to be fine. What could be other reasons for the fuel leak?"
 
Blown lower crankshaft seal is

Blown lower crankshaft seal is one.Ruptured oil recirculation line is another.Ruptured fuel pump diaphragm is another and a flooding carburetor (bad float valve ) is also a cause.
 
SSparky:
I replaced the oil

SSparky:
I replaced the oil recirculation line this summer hoping to solve the problem but it didn't. Which of the other three causes would you investigate first? Will replacing the lower crankshaft cost more than the motor is worth? (I don't believe I am capable of this repair)
 
When you pump up the priming b

When you pump up the priming bulb it should go hard. If it does not than either fuel is leaking past the float valve (drip out of the carburetor) or the fuel could go thru a hole in the diaphragm and directly into the crankcase. So does the bulb go hard?Replacing the lower crankshaft seal is not really that hard of a job.
 
""Replacing the lower cran

""Replacing the lower crankshaft seal is not really that hard of a job."

Not for an experienced mechanic, but quite a challenge for one who has not done it. The powerhead has to come off, and it has to come partly apart.

Jeff"
 
SSparky:
The bulb does go har

SSparky:
The bulb does go hard. There is evidence of leaked fuel in the front part of the motor housing but not the back. Is the gasket you are referring to positioned vertically? If this had to replaced by a mechanic what would be the approximate cost of parts and labour?
 
If the bulb goes hard i would

If the bulb goes hard i would just run this motor.Where are you located??Getting repair work done at most Marinas/dealers is becoming too expensive for the type of work you want done.
 
Back
Top