1996 Evinrude 3HP Won't Idle

[matt_southbound]

I recently purchased what was advertised as a 1996 Evinrude 4HP (I looked up the model # J3RED online, and it looks like it is actually a Johnson 3HP - not a big deal though). The seller started it up for me without a problem, and it ran fine for the 5 mins we ran it.

Fast forward to a month later, and I can't get it started on the back of my dinghy. After emptying the tank, adding new fuel, and checking spark plugs, I still couldn't get it going. I decided to take off the carb and clean it up. This did the trick, and now I've got it running.

This is the first outboard I've ever had (although I have done some work on my inboard diesel before). Although it is running now, I've got a few questions/issues that I can't seem to find the answer to.

1) There is a small knob next under the pull rope. Pulling it out turns the choke on, pushing it in turns the choke off. You can also turn it a quarter turn clockwise. This cuts off the fuel to the cup with the carb float switch. Straight up and down the fuel valve is open, filling the cup.

My question is what are the proper settings for starting and then for running, and when would you ever want the knob to the right, so that the fuel valve is shut off?

2) I'm not sure I have the idle screw set correctly. When I start the motor with the choke on, it will run for a few seconds then die. If I turn the choke off, allowing full air intake, it starts and runs fine. This is the opposite of what I thought would be the case. I'd imagine that it would run easier initially with the choke on because there would be more fuel in the mixture.

After I start it, it will usually idle in neutral or in gear OK, but sometimes it dies. If I ride around with the throttle open for a few minutes, then drop down and try to idle, it will die, and I don't know why. Maybe that's just how these motors are?


Any help very much appreciated! Thanks!

 

[gm280]

:welcome: aboard matt_southbound. Always great to have a new iboater...

Not knowing your engine, I have to ask, have you run a compression test on it to see where those numbers are? Some times with smaller displacement engines, they will run well in the upper RPMs but not idle well when you throttle back if the compression is low. However, since you did remove the carb, there easily could be an issue there as well. Do you have a factory shop manual for your engine? If not, it would be a great investment to buy. Everything you ever wanted to know will be in the factory manual. I am sure others will chime in and help you out with this engine. JMHO

 

[matt_southbound]

Thanks for the reply. Good tip on the manual, the motor didn't come with one, but I'll order it. I have not done a compression test, simply because I don't have a tester yet. It's on my list of things to pick up next time I'm at a hardware store (I'm currently aboard my sailboat cruising right now).

 

[oldboat1]

Gotta love it! Out cruising....

Your motor is 20+ years newer than the "newest" 3s I fool around with. Having said that, I don't think it's remarkable that the motor fires up and runs with the choke off -- in particular if the engine is warmed up (or at least not stone cold).

On the stalling, I would try to tweak the air/fuel mix a little richer (1/8 turn or so counterclockwise, at least on my oldies). This stuff can be counterintuitive, though, at least to me. Stalling could also be due to an overly rich air/fuel mix -- engine stumbles and stalls.

I find it easier sometimes to just start over. Set it to the standard initial setting (about 1 turn open from lightly seated on mine, maybe a little more). Then let the motor warm up and slowly adjust leaner (clockwise) until the engine sneezes or stalls, then back it out about 1/4 turn -- often close to the final setting. Test by shifting in and out of gear a few times. If it wants to stall, tweak it a bit richer.

If you run on an integral tank, I see on the parts diagram there is an inline filter. That could be an issue (clogged or maybe in backwards).

Sounds like a nice motor -- will run like a little sewing machine, if like the old ones.

 

[Crosbyman]

delete

 

[Bonaventure]

When you use the engine, you should shut the fuel off when you are finished and run the engine until the fuel in the Carburetor is burned off. This leaves the carburetor bowl dry and helps to keep things clean. It also prevents fuel from running out of the motor when it is laid down for transport. You should lay the motor on the side away from the fitting on the fuel tank ( fitting side up) and also ensure that the fuel cap vent is closed. These measures will also prevent fuel from leaking into your vehicle.

 

[Bonaventure]

I looked at a diagram of the fuel tank, it looks like there is no vent on the fuel filler cap. I also looked at the carburetor, the slow speed adjustment does not have a knob like earlier versions, it appears that you need to remove the air silencer to adjust it. It is preset by the factory and probably not intended for the owner to adjust. There doesn't appear to be a high speed adjustment on this Carb.