1975 50 hp evinrude run and die after 1 or 2 minutes

digong

Cadet
Joined
Apr 26, 2019
Messages
20
Hi Experts, i brought my boat to the lake and the motor will run but die or stop after a minute or so, sounds like running out of fuel, i have new fuel line and new fuel pump, new fuel with the right mix 50:1, appreciate your help and suggestions, thank you in advance.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,455
How did it run the last time you had it at the lake ?------What happens when assistant operates the manual pump ?
 

digong

Cadet
Joined
Apr 26, 2019
Messages
20
This is my first time to bring to the lake, i have only ran using muffs, crossby seems right that it is sucking air than gas, the both fuel lines are new especially the 2nd 1 as i thought the other was broken, couple of months ago it was tuned up by a shop and comments are good overall, thereafter i ran once in a while in muffs in prep for summer.
 

digong

Cadet
Joined
Apr 26, 2019
Messages
20
I also tried to help by pressing the bulb while running but st some point it will run out of gas it seems,, again appreciate your thoughts and comments.
 

digong

Cadet
Joined
Apr 26, 2019
Messages
20
Yes it is, please dont apologize, i appreciate every comment and questions from you guys as you are the expert, i am loving the experience of having a boat even though it is very old but it is what i can afford.
 

digong

Cadet
Joined
Apr 26, 2019
Messages
20
Thought to clarify that as part of starting, i open the vent and later close it as the motor get stable
 

spybot

Chief Petty Officer
Joined
Jul 4, 2016
Messages
504
Thought to clarify that as part of starting, i open the vent and later close it as the motor get stable

Are you not getting the Vent on the tank confused with the choke on the engine ??
 

digong

Cadet
Joined
Apr 26, 2019
Messages
20
Manual choke lever set at bottom which show the choke valve close, thank you.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,455
If it is an original OMC steel tank with the 2 wee pins it will vent when you plug the hose into the tank.-----Tanks must vent somehow for fuel to get to the motor.
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,658
older tanks don't vent they need the screw cap vent openned and cleaned to make certain they are not crudded shut

in any event try the moter with the gas tank cap off for a test

if ok vent is crudded shut
 

JerEazy

Petty Officer 1st Class
Joined
Jul 26, 2017
Messages
234
Have your same motor:

Does it have trouble starting at all? Like extra turn over etc? What RPMs will it rev to before it “runs out of gas”? (under load in gear - not just tied at the dock)

compression check? Spark check?
 
Last edited:

digong

Cadet
Joined
Apr 26, 2019
Messages
20
Thank you all for your comments, just ran it now, same issue, i decided to get another tank Neptune brand, as soon as i ferl that the bulb is full, it will run and die after fuel is suck i guess as the primer get softer, there seems to be no continues fuel going it as it sounds like it is starving, compression on both at 135 psi and sparks are good as tested at the shop when i brought for tune up 2 months ago, they adjusted idle at to 1000, tested crank case leak and they said its good, the only negative comment on my bill is a lil milky leg and this was due to the drain and fill plug not tight enough, i ordered two washer and works fine now, after running on barrel oil seems ok, on starting, it start easily if valve are open or i spray the carb with fuel, i am thinking to go back to the shop hoping they can fix it, i dont want to cause so much time on you All who are patiently reading and providing insightful thoughts...thank you so much, due to the trouble it has, is it alright set-up wise if i decide to replace the motor. with a newer one same 50 hp, as long as the weight are approximate thesame? with zero knowledge on outboard i think it is challenging to keep the motor,,, again thanks all i could have sound stupid with my questions but its nuce to learn it,,it is very interesting...
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,658
back to square one… you must answer questions yes or no

did you take the carb apart to flush all orifices with carb cleaner ? the blow dry them with high air pressure
did you remove the lower plug on the carb and look-see for light in the high speed jet hole while carb was apart ?
did you inspect the float setting ? float should b parallel to carb body
can you disconnect the fuel hose at the carb and feed the carb with a small fuel container held above the carb - post results of the test … if the engine runs work the issue backwards to the gas tank dirty pump screen ??

by the way can you perform a blow test on the carb no air should enter the fuel inlet with the carb held upside down
air should flow into the carb when held right side up … post your results
 
Top