Nissan outboard dies occasionally

[Fishfighter]

I've got an 18hp nissan outboard 2 stroke that has been causing me this one problem for quite awhile.  It runs great initially and then after quite awhile it spits, sputters and dies. The primer bulb is soft when this happens and I just re prime and start it up like new again and off I go. It does not do this every trip and never more than 2 or 3 times during a full day of fishing.  I really think it is pulling air in somewhere. It does have the quick connect fittings. These were put on a new epa hose assembly, all new last year and I just bought the outboard then so I can't isolate the problem.  The tank was also new and I have the vent open on the tank.

 

Thinking about ordering a new hose assembly with fittings but thought I would mention it here first. 

Any ideas?

 

 

 

[fishinwrench]

Sounds like you've narrowed it down to a fuel supply/delivery issue.  If the bulb goes completely empty and it takes more than 2 squeezes to reprime it then it is indeed siphoning back down. 

Consider the finger over the straw scenario. How many different ways are there to cause that vacuum to cease and the soda to leave the straw?  

Lift the finger.

Put a hole in the finger.

Put a hole or crack in the straw. 

 

The fuel pump diaphragm is the finger.

[Fishfighter]

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