1969 evinrude 18hp dies periodically!!

[bodiesel]

Engine starts fine but loses power and dies after a few minutes. Ive noticed some oil/fuel collecting in the bottom of the housing, which may or may not have anything to do with it. carb was cleaned at the end of last season, and it has a new fuel pump on it. Any advice helps. Thanks.

 

[Rick.]

Re: 1969 evinrude 18hp dies periodically!!

Make certain your tank is vented properly. When it is about to die try pumping the primer bulb and see if it responds. Also you should check for a good spark with a spark tester. I know you cleaned the carb. but that might be something you'll have to do again. Let us know how it goes, best of luck. Rick.

 

[bodiesel]

Re: 1969 evinrude 18hp dies periodically!!

When I was out there, I did try squeezing the bulb and it didn't do anything, and the vent is good on the tank.

 

[jbjennings]

Re: 1969 evinrude 18hp dies periodically!!

Is it really hard to restart after it dies like that? Is there fuel leaking out the carb. throat when it dies? If so, your float needle and seat isn't working right and it's flooding the motor.
If none of the above, I'd get a $6 spark tester and check spark on both cylinders.
good luck,
JBJ

 

[bodiesel]

Re: 1969 evinrude 18hp dies periodically!!

well, I just took the carb off and its clean and the float and needle seem to be working well. WTF!

 

[coolguy147]

Re: 1969 evinrude 18hp dies periodically!!

check spark probably interminent

 

[jdsgrog]

Re: 1969 evinrude 18hp dies periodically!!

does the motor die at idle? does it die when you rev it up? more info can be helpful. did you check compression? spark? too many "possibilities."

 

[chief08087]

Re: 1969 evinrude 18hp dies periodically!!

i had an old 18 horse around that year and would do that. my exhaust was filling the hood up with smoke and killing the motor. just a thought

 

[jbjennings]

Re: 1969 evinrude 18hp dies periodically!!

The tiniest imperceptible piece of trash in the float needle seat will keep it from closing all the way. Try pumping your primer bulb until it gets hard, signifying the float needle closed, preventing any more fuel from getting into your carb. Does it get hard?
You never said whether or not it was hard to crank after it dies, or if it cranks right back up. Or if any fuel was running out the carb. throat after it died. That info would be helpful to me.
What is your motor doing before it dies? Is it idling or what?
Does it kind of "cough" or "sneeze" just as it dies?
Need more info. to give decent help....:redface:
JBJ

 

[bodiesel]

Re: 1969 evinrude 18hp dies periodically!!

sorry about the lack of info! well, the bulb does get pretty hard when it's pumped, and it starts right up after it dies. There's just a little bit of fuel puddled in the carb throat, and no cough when it dies. It dies when the throttle is high and when it is idling, and I don't have a compression tester or a spark tester yet, but I'm working on that!

 

[jdsgrog]

Re: 1969 evinrude 18hp dies periodically!!

Ive noticed some oil/fuel collecting in the bottom of the housing,

Which housing? if it's leaking into the engine pan, then you should try to find where the leak is coming from. also, have you adjusted the needle valves? I'm not sure if that year had both high and low speed needle valves, but i know that it at least has low speed. i am wondering if it is a float problem. I know you said you checked it, but if the float is not closing the needle, then it may be pumping too much fuel into the carbs causing an "overflow" of fuel.

Also, you said that the carb was clean. did you clean the carb yourself by letting it soak in cleaner. when i first started working on one of my motors, i thought the carb was clean because it was visibly clean, but i still had idle problems. i then took someone's advice on these forums to be sure to soak it overnight and blow out the jets with compressed air. i did so and it solved my problem.

 

[po1973]

Re: 1969 evinrude 18hp dies periodically!!

my '68 18HP Fastwin had similar problems periodically until I replaced the coil/points/condenser under the flywheel. Parts were about $60. That motor really goes now!

 

[jbjennings]

Re: 1969 evinrude 18hp dies periodically!!

If it starts right up after dying, it isn't flooding out I don't think.
Since it dies at idle and high speed, I'm really kind of baffled. I think you may have a short in your kill switch wires, or the kill switch itself. That's about all I can think of.
Good luck,
JBJ

 

[jimjoe420]

Re: 1969 evinrude 18hp dies periodically!!

is it over heating? mine was doing this. it would heat up and die and would not start for about a half hour. it ended up being the impeller. it had me baffled.

 

[bodiesel]

Re: 1969 evinrude 18hp dies periodically!!

Idon't think so because it starts up right away after it dies