'78 Merc 850 High RPM fuel problems

smerkal

Recruit
Joined
Jun 28, 2003
Messages
4
Having troubles with motor running out of fuel at high RPM's or under heavy load. It also seems to lack a little power out of the hole. When it begins to act up, pumping the primer bulb brings it out of it. Have replaced fuel pump diapragm and check valves. Cranking compression is 130 across the board. Fuel tank vents operate. Lines and primer bulb are new. Engine sat for about 5 years but do not know how it ran previous.
 

smerkal

Recruit
Joined
Jun 28, 2003
Messages
4
Re: '78 Merc 850 High RPM fuel problems

One other note, primer bulb never seems to get hard. Motor starts right off after a few pumps, idles smooth but the bulb will never get hard.
 

tradin

Petty Officer 3rd Class
Joined
Jun 26, 2003
Messages
98
Re: '78 Merc 850 High RPM fuel problems

sounds to me like you should check all the carb lines mine was acting up and i found 2 real small gas lines were leaking at high rpm.s the are 3 or 4 half inch lines in there hope this helps
 
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