fuel line assembly for old merc ... ?

[sjbpdx]

hello!
can someone out there tell me what type of fuel assembly i need for my 1971 mercury thunderbolt (50 hp)? is it just the standard mercury one? also -- where in the heck is the fuel filter on this motor? i seem to have a fuel issue. my motor doesn't seem to get the flow of fuel it needs. so i'm starting with the obvious.

thank you!

 

[Chinewalker]

Not sure what you mean by fuel assembly. Do you mean the fuel line? The fuel pump? The filters - there are two - are located on top of each carb.

 

[sjbpdx]

it's the hose that connects the motor to the fuel tank. it's got a bulb in the middle of it. one end has a male/female connector that goes to the fuel tank. the other end has a t-like connection that fits into the motor. my original outboard was a 1959 evinrude and i've 'upgraded' to the merc. i am wondering if i am even using the right fuel line assembly. my boat will stay running when at full throttle ---- but if i slow down or idle after it's been running for a while, it dies. it feels like it just isn't getting gas.

 

[MH Hawker]

Have you tryed pumping the ball when it isnt running right.

 

[sjbpdx]

i've done that and it seems to have a slight effect. i guess it's a process of elimination, eh?!

 

[inthedirtagain]

I had to bypass my original 1969 Merc 1000 fuel line and adapted a line from my Evinrude kicker. I found that the fuel doesn't want to flow if the bulb isn't oriented the right way. Double check that the arrow on the bulb is point towards the motor. There are one-way check valves in them that are supposed to prevent fuel from draining back into the tank. When my camera decides its going to work, I'll upload photos of the fuel fittings on my Merc and Evinrude tanks to show the differences.

 

[Chinewalker]

If you're talking about the fuel line itself, the motor doesn't care what you use. All fuel bulb & line assemblies accomplish the same thing the same way. Only differences might be in fuel line diameter, .ie you don't want to use a tiny fuel line & bulb from a little kicker on a big V6. Fuel line assemblies for your 50 should be standard 5/16" hose. You can get complete assemblies with connectors or without, right here on i-boats.

 

[sjbpdx]

i'm having a heck of a time matching up the right fittings and connections. i got a brand new fuel hose fitting -- it's a Mercury 3/8" (West Marine part #13854518). it connects and snaps in just fine to the brass fitting that's connected to the gas tank. the arrow on the bulb is pointing in the direction of the motor. however, when i pumped the bulb, gas was leaking out of the fuel hose fitting. no gas is getting to the motor as it won't even start now. i've attached a picture of the entire assembly. i've also attached a picture of the new hose fitting sitting next to the old one. the problem with the old one is that it wouldn't stay on and kept popping off. i am wondering if i've got the right hose fitting now.

 

[sjbpdx]

update ::: the one on the left is crap. it never sealed. i made two trips to West Marine for this little part. apparently they sell some after-market items that are not even compatible with the brands stamped on the boxes. i went into Cascade Marine ... you know, an actual dealer & repair shop. it took the guy 1 minute to locate the right fuel line connector. the seal was airtight. and the boat fired up after i pumped some gas to the motor. i kept it running for a while -- both idling and high speed to run the fuel through. it died a couple of times ... just puttered out after idling. i pumped it again, and she stayed going ... purring in idle mode.

so ... now the true test will happen this weekend. i've got her cleaned up ----- ready for the lake. i am pretty confident i will still encounter some fuel issues.

it's amazing what a difference an $8 part can do. also -- lesson learned on getting parts from West Marine. i think i will stick with the family owned friendly Merc dealer.

 

[enginepower]

Sounds like your fuel pump has a tear in diaphragm and/or you have water in fuel