1977 70hp evinrude fuel line attatchment issue

[roonie]

I have two older metal tanks with this boat/engine. They do not have the air vent screw on top the cap so i have to loosen the fuel cap a half turn or this engine will die.

Another thing i have noticed is the fuel bulb seems like its being sucked up and not full looking but yet there is fuel in it even with the fuel tank lid open 1/2 way.

I have had intermittant issues with this engine stalling at trolling speed and what seems like starvation of fuel at upper speeds. I cannot come to any concrete conclusion to this dilema so far. Many times the boat runs like a charm...but then the issues arrise again.

when i run out of the first tank of fuel and switch to the second tank I seem to have an issue with getting the second tank to start and run smooth. The engine kicks and bucks and seems to have some sort of air lock issues even though ive pumped up the fuel bulb. One thing i have noticed is when pushing the clip on fuel line to the tank, the clip seems to fall back a wee bit and does not butt up tight against the tank male end.
Is this fuel system supposed to be closed?

I was told by a boating friend that there is an "0" ring inside the clip on side of the fuel line that may be worn.
Anyone have any ideas as to my issues...cause i sure dont know where to go from here. I hope ive been clear. Thanks

 

[sutor623]

Re: 1977 70hp evinrude fuel line attatchment issue

Do you have another gas tank that you can try? When I switch fuel valves and tanks I make sure that the first tank never runs dry to keep all air completely out of the fuel system.

 

[roonie]

Re: 1977 70hp evinrude fuel line attatchment issue

thanks pete. I have two tanks and never think to check the fuel guage due to the tanks being located waaayy under the back of the boat. Just wondered if anyone had any insight into those "0" rings in the female end of the fuel line.

 

[roonie]

Re: 1977 70hp evinrude fuel line attatchment issue

any idea as to why my primer bulb is always half sucked in looking? It never looks like a full shaped bulb and does not seem to have any air in it...just fuel?

 

[boobie]

Re: 1977 70hp evinrude fuel line attatchment issue

Fuel restriction on the tank side or bad primer bulb.

 

[sutor623]

Re: 1977 70hp evinrude fuel line attatchment issue

Fuel restriction on the tank side or bad primer bulb.

Yup. If you had air in the line because of a failed O ring, the bulb would stay inflated and soft. But if the clip does not sit tightly, you may need a new male end. Push the little nipple in on the male end and see if it is free.

 

[dazk14]

Re: 1977 70hp evinrude fuel line attatchment issue

Fuel tank dip tube - bottom of tank end - filter is likely clogged. Very common issue on older tanks.

While you have the dip tube housing out (4 screws), you can isolate why the auto-vent isn't functioning. Parts are available.

 

[boobie]

Re: 1977 70hp evinrude fuel line attatchment issue

You can check at shop.evinrude.com for parts for your tank if needed.

 

[roonie]

Re: 1977 70hp evinrude fuel line attatchment issue

Thanks so much for this. Is it worth fixing these older tanks especially that fact that these tanks have no vent screw on top the cap? Maybe i should just go buy two new plastic tanks? Can the older tanks be cleaned and if so ...how and with what?

 

[roonie]

Re: 1977 70hp evinrude fuel line attatchment issue

I think i may have found my issue. Not sure yet till i take her out on a run but the two hose clamps at either end of the fuel tank hose were somewhat loose. They were not falling off but they sure were not tight either. Just thought i would post this up as i hate it when guys dont call back in with findings..........kinda leave guys hanging if ya know what i mean.

 

[Home Cookin']

Re: 1977 70hp evinrude fuel line attatchment issue

I think I'd replace the bulb. I was recently starting up an old motor I hadn't run for a while and found I had not one but two bad bulbs; I switched tanks, too.

But don't buy a new new tank; they don't have vents at all! Go to the yard sales, or stick with the old loose cap version.