I have replaced the fuel water seperator and the fuel line from the primer bulb that i replaced with a mercury bulb , I have checked the vent line and the fuel fill cap and both checked out fine , A buddy told me to check the siphon tube it may have a crack in it , I was also told to check the anti siphon valve is there any other suggestion that I should check thanks dmackfire. this is very flustrating not knowing what is wrong.
Remove the anti-siphon valve and pickup tube from the tank. Check the tube for cracks, and the anti-siphon valve for debris stuck in it.
It is also possible that you have a "fuel pump" issue (such as a pulse pump in need of rebuilding).
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Call me stupid but can you explain a pulse pump and give me a discription of one ,is it the electric fuel pump on the right front of the motor , i"m going to check the siphon tube and the anti siphon valve can I clean the anti siphon valve or do I need to replace it
Fuel line goes into cowl and runs to a 2 inch square pulse pump on the side of the motor. Cheap to buy a rebuild kit and instructions are included for install.
Richard
Above fuel pump description is correct.
If the anti-siphon valve is at all "questionable"- replace it.
Pickup tube- inspect carefully for cracks, pin holes, or blockage.
Incidentally... a good way to "confirm" that the problem is in the tank or lines is to connect a portable 6 gallon fuel tank, with it's own fuel line directly to the engine. Run the engine and see if the problem is gone- if it is, you've "disconnected the problem"
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Does it run out of fuel on long idles out to boat runs,if pick up tube was split you would not be able to pump bulb firm,the check ball could be trashed up or sticking,but sounds like the check valves are warped or curled up in the pulse pump,1999 probably has the old style valves in it instead of the mylar valves.
Don't "ignore" the pickup tube... they can be tricky to find! If there's a crack or split, say 1/2 way down the tube... you may be able to pump the bulb firm (provided the fuel level is above the split/crack), but as the boat changes it "attitude" in the water (and fuel moves to the other end of the tank), you may suck air.
For experiment... cut a slit in a straw, 1/2 way between the ends. Immerse straw in full glass of water and drink through the straw. No problem... until you reach the "slit" that you cut.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Does the problem happen with a full tank,half tank,quarter tank,most pickup tubes split were it it is swedged to the tank fitting up top,dont jump me for this,I said most not all,most boats are easy to remove and check.When it runs out of fuel can you pump the bulb firm and recrank and run for a while,if you can then IMO its not the tube.
Sounds like the fuel line is coming apart inside if it the original gray line that came on the boat more than likely the problem. If the line is real soft thats a good sign the inside has come lose and causing a restriction.....OPTIMAN
North Texas Marine ....Fort Worth......Mercury Master Technician ....MERCURY,OMC,SUZUKI,YAMAHA
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