1981 15hp Evinrude hard to start--need advice

[oldboat1]

Sounds like it might be running hot. Check temp when it wants to act up. In addition, pull off plug boots one at a time. If you pull off a boot and get no change, chances are it's not firing on that cylinder.

 

[racerone]

Going to say the facts here, sorry-----These are a fine engine.-----If they are " hard to start " then there is something wrong with the engine or the starting procedure.----Trouble shooting needs to be done !

 

[AlTn]

add to the fuel side of your trouble shooting...run with the fuel tank cap being loose as it may not be venting properly causing a vacuum to form in the tank which the fuel pump can't overcome

 

[OptsyEagle]

OK, so a lot of confusion here. You adjusted the cam/roller screw and then had problems starting the motor. That would do it. I suspect you adjusted it back correctly so that the mark is in the middle of the roller when the roller hits the throttle cam...and now she starts...but dies when you try to idle it down.

You also said that you did not fiddle with the rich/lean screw on the carb after the carb cleaning. Well it's time to fiddle. Turn it in slowly (clockwise) and determine how much you turned it when you lightly bottom out the screw. Never hurts to know where it was. Now turn it counter-clockwise 1.5 turns and start up the motor. If it stays running, let it warm up. Bring the idle to as low as you can and dial the needle clockwise 1/8 of a turn. Keep doing this. If the RPMs start to increase, reduce the idle with the throttle grip. Again, turn in the dial 1/8 of a turn at a time, giving the motor 10 seconds to respond each time. Eventually the motor will hiccup, cough and want to staul or will staul. Turn the dial counterclockwise 1/4 turn and leave it alone. It is now correctly set and should never need to be touched again until the next carb cleaning.

If the motor will not stay running, my guess is the carb cleaning was not done well and needs to be redone.

 

[boobie]

Edit...........

 

[biologicole]

OptsyEagle...that's what we did the other night and we're starting to get it dialed in. I also agree that the carb is still suspect. When we quit the other night we had it figured out and working fairly well in two different ways--the low speed idle worked good but it was difficult to start, OR, it stalled at the low end but was easy to start. I'm using it for duck hunting on the weekends and usually run it about 1/2 throttle in the marsh so it's currently set for the easy start option.

Tinkering with this engine and trying to get it right has moved from a challenge to an obsession, LOL. I'll win eventually. Advice from here and having a manual has definitely helped.

 

[biologicole]

Racerone you suggest the problem might lie in the starting procedure? what starting procedure do you suggest?

 

[oldboat1]

Not to step in or on, but have some hands-on experience that's probably close.

My 9.9 Yachtwin ('83) has the mid-sized jet in a 15 carb body, so operation might be similar. I tune the idle air mix for best running when warm -- find cold starting works best if I first open the needle 1/4 turn (set back to the normal leaner setting when the motor warms up). Procedure is to set the mix richer, pump the bulb until carb bowl is full, give it full choke and crank it. (Choke turned off right after it starts, although I sometimes have to feather it a little.) This is a trolling motor on a larger boat -- sits in a slip out in the weather, usually tilted up between uses. It's electric start so might crank a little quicker than pulling it over, but not sure of that.

 

[OptsyEagle]

I assume you have the throttle turned until it stops on the neutral stop, when attempting to start the motor. As opposed to using those unreliable words on the twist grip to position the throttle for starting. Let us know.

The other question is to confirm that you have actually seen the choke butterfly close in the carb throat as opposed to seeing the choke knob fully open, or hearing it click when you pull it, or seeing the choke lever move when pulled. Those are interesting but the choke can still be open when those other three things are present. If you haven't done this yet, remove the cover on the air silencer and visually ensure the choke butterfly is closing fully when the knob is pulled. I state this because I had a 1976 15HP where the knob would pull properly, you would hear the regular click and even the lever would move somewhat but in the end my choke was being kept open due to some wiring interfering with it below. I don't need to tell anyone she was a real bear to get started. Oh, who am I kidding. On the cold mornings she didn't start at all.

 

[thatone123]

I know that for many older OMC small outboards the standard 1 1/2 turns works for the carbs. The idle screw on the latter Mexico plastic topped 15 carbs is how many turns?

 

[biologicole]

It was 23 degrees when we got started Saturday morning and the engine would have started on the third pull if I could?ve got the choke pushed in quick enough. It ran well and idled down after about a 45 minute drive. I let it sit about six hours and it fired up on the third pull and ran fine all the way back to the boat ramp but died when I tried to idle it.

I haven?t actually looked in the carb to see if the choke was opening and closing properly but I?ll do that this week.

All in all I?d say it?s starting and idling better but still has a ways to go. We?re definitely on the right track though.