Merc 500 fuel problem

[Greg New Zealand]

My 4 cyl '77 merc 50 is pull start. Always starts up OK but after being turned off (even 5 mins) I need to pump the primer up again to start it. Sometimes, if I just idle after a re start, it will die. If I give it some revs straight away it will be fine. Is this a check valve problem or fuel pump diaphragm? <br /><br />The motor is a real sweetie- will run WOT all day with no problems - it's only the stop/start thing that bugs me. Any suggestions will be appreciated.<br /><br />Greg

 

[Barnacle_Bill]

Re: Merc 500 fuel problem

Check all the fuel lines and make sure they are soft and pliable (no cracks). Replace the primer bulb. They are the first to go. If you still have a problem, rebuild the pump.

 

[WillyBWright]

Re: Merc 500 fuel problem

Might as well do both the bulb and the pump. For less than $20 American you can get a bulb and a pump kit. If that pump has never been rebuilt, it's long overdue.

 

[dolluper]

Re: Merc 500 fuel problem

your fuel tank vent is open if so check all lines for leaks sucken air will show up at idle

 

[Greg New Zealand]

Re: Merc 500 fuel problem

Thanks all<br /><br />The kit is a cheap way to start the elimination process.