ELECTRIC FUEL PUMP/Can I be sucking in air instead of fuel at top end?

[captin 420]

I have a problem with the 78 merc 850. The is no top end. What type of pump should I use. My motor run when my buddy presses the bulb. I've cleaned the carbs and put a new fuel diaphram in. I don't know what else to do? What are the floats? Can I be sucking in air instead of fuel at top end? How can I fix.

 

[The Marine Doctor]

Re: ELECTRIC FUEL PUMP/Can I be sucking in air instead of fuel at top end?

When rebuilding the fuel pump...did you replace the checkvalves in the pump? There should be 2 of them. If they are fouled...there will be poor pressure or none at all.<br /><br />TMD

 

[suzuki40]

Re: ELECTRIC FUEL PUMP/Can I be sucking in air instead of fuel at top end?

^

 

[fgbutler]

Re: ELECTRIC FUEL PUMP/Can I be sucking in air instead of fuel at top end?

Had a similar problem on my 71 Merc 800. Cleaned my carbs twice and replaced all fuel lines. Found my timing was off.<br /><br />I have found that electric fuel pumps are a bad idea. People like to blame carburators and begin adjusting them unnecessarily. Get fresh gas. Alcohol overtime adds moisture to gas. Check all lines for air leaks and clear any obstructions. Last of all check your timing, but I would not screw around with that without a manual.