Logo

1984 Evinrude 15 Hp needs prime?

FCcarp

New member
After the motor sits for a while in order to start I have to pull the plugs and prime with some gas then fires right up.
Runs smooth and restarts with one pull. After sitting for more than a couple of hours then same prime issue.
New plugs are in place. New gas and bulb pumps up tight.
Obviously not getting gas and after sitting gas drains out. How can it not draw gas after 2 or 3 pulls but draws once started.
Any ideas?
 
With that cylinder prim startup method... if the engine runs normally, the carburetor is obviously full of fuel or else it would stall out as soon as the fuel in the cylinders expired. You said nothing about pumping the fuel primer bulb up again.

When the engine is first started for the day... do you need to do this cylinder prime setup? If so, I'd suspect that the choke butterfly isn't functioning for some reason.
 
With that cylinder prim startup method... if the engine runs normally, the carburetor is obviously full of fuel or else it would stall out as soon as the fuel in the cylinders expired. You said nothing about pumping the fuel primer bulb up again.

When the engine is first started for the day... do you need to do this cylinder prime setup? If so, I'd suspect that the choke butterfly isn't functioning for some reason.



First start of the day requires plug pull and prime. After that no problem. Don't need to pump up bulb again. Time between re-starting ok and not starting varies. May start fine the rest of the day then next time out wont re-start after a couple of hours and have to prime again. Once I have it started I can slide the choke in and out and see rpm change so I believe choke is working.
Thank you for reply.
 
It sure sounds like the choke. You should take off the air silencer cover and visually observe that the choke butterfly is closing. Sometimes the choke lever appears like it is working fine, when it is not. Your problem definitely sounds like a non-choking issue.

The other lesser probability is the link and sync of the carb. Make sure your carbs roller is lined up properly with the throttle cam. Perhaps your motor is not getting enough gas to start when cold due to an out of alignment link with your carb.
 
It sure sounds like the choke. You should take off the air silencer cover and visually observe that the choke butterfly is closing. Sometimes the choke lever appears like it is working fine, when it is not. Your problem definitely sounds like a non-choking issue.

The other lesser probability is the link and sync of the carb. Make sure your carbs roller is lined up properly with the throttle cam. Perhaps your motor is not getting enough gas to start when cold due to an out of alignment link with your carb.

Will check the choke but your second comment regarding the roller to cam alignment is interesting. I find that when cold and first starting, turning the throttle to full for start does not seem to roll all the way to full position then after started it seems to loosen up like something changed or got out of the way and the throttle rotates more fully. Will look into this. Thank you.
 
Will check the choke but your second comment regarding the roller to cam alignment is interesting. I find that when cold and first starting, turning the throttle to full for start does not seem to roll all the way to full position then after started it seems to loosen up like something changed or got out of the way and the throttle rotates more fully. Will look into this. Thank you.

Roller cam was hardly getting touched when turning throttle to full for first start up. Gave small screw a couple of turns to adjust and this pushed the
throttle open just a little and Voila! started without prime.

Thank you for your thoughtful insight. Will keep my eye on this.
 
I am having a similar problem with my 1978 Evinrude 15Hp, except with mine it takes about 10 pulls when cold to start. When it is warmed up usually only one, unless it sits for an hour or more then several pulls. Next day back to 10 pulls.
 
I am having a similar problem with my 1978 Evinrude 15Hp, except with mine it takes about 10 pulls when cold to start. When it is warmed up usually only one, unless it sits for an hour or more then several pulls. Next day back to 10 pulls.

My problem went away after I adjusted the small screw just below the cam wheel that gets pushed forwards when the throttle is placed in the full position to start. Cam wheel was not being pushed far enough forwards to open the carb and let enough gas in. Caution, after the adjustment it now starts fine but at very high rpm so cut back on a full open throttle start.
Replacing plugs is also recommended.
 
My problem went away after I adjusted the small screw just below the cam wheel that gets pushed forwards when the throttle is placed in the full position to start. .

The throttle butterfly should just start to open when the scribe mark on the cam is dead center with the throttle roller. Is that where you sat it?
 
Back
Top