If the bulb is backwards, I am surprised the motor runs at all.
If the bulb is backwards, I am surprised the motor runs at all.
Bulb is right. Just noticed the arrows on the fuel lines earlier. Thanks for the help.
Had a fuel delivery problem. Dealer used a known good tank of fuel and motor performed very good.
took the fuel line off the barbed fitting and the inner hose lining had rolled up inside the outer hose upon installation of bulb and was restricting fuel flow.
corrected problem and it now runs great.
May be worth investigating inner hose at barbed fittings.
Thread #3 stated to check the Fuel Demand Valve, what are the results of this test? If it has not been checked, then it needs tested before going any further.
What is the fuel demand valve and how is it checked?
FDV (fuel demand valve) is a device that prevents pressurized fuel in the fuel tank from being forced into the engine's fuel system. When the engine's fuel pumps draw a vacuum (demand) on the valve, it opens and permits fuel to flow through. It closes as soon as the demand ceases.
Description of operation basically describes how to test it as well.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Where is it located?
Somewhere between the level of fuel in the tank, and the engine. Boat Manufacturer (Jan 2011 and later boats) specifies the type and setup of the boat fuel system, for built-in systems.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
I don’t think I have one of those unless it’s mounted in the tank. I have a vent hose mounted to my tank, the fuel gauge unit, and the fuel pickup is all I see coming out of the tank. Then it is a straight shot of fuel hose to the primer bulb then to the motor.
What boat (and what year is the boat)?
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
1.5 yrs. with the same problem......Fuel Issue
This boat does not have a FDV.
Connect a hand vaccum pump to the fuel line.
If it pulls a negative vaccum then you have a restriction. We have listed all the possible cause for restrictions, so it is up to you to examine the components, and find the restriction.
This is NOT a motor problem, it is a fuel line, or tank issue.
Last edited by Savage; 04-04-2019 at 05:48 PM.
Thanks for all the input. I am gonna troubleshoot some more next week. I’ll post the results.
Savage have you had this issue with your boat before? “1.5 years with the same problem”
It appears you have from an earlier post.
When this happens again while the bulb is flat, remove the gas cap. If the there is a vacuum present or you see the bulb start expanding, you have a vent problem. if it does not change, remove the fuel line from the tank again watching the bulb, if it expands you have a restriction between that point and the fuel in the tank. Keep doing this until you pinpoint the location
Thank You Leon Pugh
Thanks!! I’ll try this
No, you have had this same problem for 1.5 years...….http://www.bbcboards.net/showthread.php?t=846100Originally Posted by MC20
It happened back then. I changed the bulb and it never happened again until the end of last year. Now it is pretty consistent happening almost every trip. I was confused and thought it had happened to you. Thanks again for all of yalls help!! Hopefully get to work on it this week. Thanks for the help.
After much time and effort, finally found the culprit. Found two small pieces of plastic from when the tank was drilled for pickup and vent lines. Also found two round caps from under the caps on the fuel additive bottles. Also, the mechanic said the pickup tube was cut flat on the bottom. He said this would allow trash to get sucked to the tube and stay there. He cut the pickup tube on 45 degrees on the bottom before reinstalling. I have had two trips now with no problems. Just want to say a big thank you to everyone here for all their help!!!
who pulled and cleaned tank in post #1 hmmmmmm ???????
.................................................. ...the scariest thing in life is the unknown ...................................
Really......who missed the "fuel additive bottle caps", when the tank was "pulled" and "inspected"????
REFUND!Also, the gas tank has been pulled and inspected and found clean with no trash or obstruction.
Reply With Quote
