Evinrude 3hp outboard help please

[tom horner]

Hi there i have bought a evinrude twin cylinder outboard engine, its in good condition and believed to be late 1980's early 1990's, the engine starts well but when i rev her at full power under the engine "dies" and wont run, unless i take the revs down then she will run fine maybe half revs but at soon as you give her full throttle she runs brilliant for a good 10 seconds then she dies again, i have cleaned the carb and jets out and the tank and dont know what to try next, has anyone got any ideas on carb set up ect? Many thanks in advance.I dont know if you need any serial numbers but it says;

MOD NO BE3BRCEC

SER NO B1929990

Regards Tom

 

[VicS]

Missed your post! so has everyone else it seems

The model number indicates that it is a 1989 model ( CE are the date letters for 89). Made in Belgium. Standard ( 15") shaft length

Its always worth starting with some new plugs. The currently recommended type is Champion QL86C although originally I think they would have been RL82.
The nearest NGK equivalent is BR6HS.
The recommended gap is 0.030" ( originally it may have been 0.040").
(L86C and B6HS would be acceptable unsuppressed plugs)

Also check that you have two good sparks. If not coils and points will need investigation

I'd think your problem is probably fuel related. Either a poor fuel supply or still some muck in the carb.

Does partly closing the choke make any improvement. If it does it probably points to there still being some dirt in the carb .... in the high speed nozzle assembly

Are you using an integral fuel tank or a remote tank.

There is no filter on the integral tank AFAIK but there is one to check associated with the fuel pump if you are using a remote tank .

Check for a good fuel flow to the carb from an integral tank.

If using a remote tank air leaks at the connector are a possibility.

If you are using a remote tank does pumping the bulb help?

Check that the float needle valve is opening properly and that the little spring clip linking the needle to the float arm is in place.


Not an issue if it idles Ok but the instructions for adjusting the idle mixture screw, after pulling off the knob, are

Carburetor Adjustment - Single slow speed Adjustable Needle Valve
by J. Reeves

Initial setting is: Slow speed = seat gently, then open 1½ turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.
Refit the knob in the centre of its adjustment range​

 

[tom horner]

Thanks for your help, i have put two new plugs in and touch wood seem to have sorted the problem, when the bottom cowling was on it was kinking the fuel line slightly when it was fitted, i taken the bottom cowling off and tryed it and she goes sweet as a nut, the only thing i would say is if you turn it off in the water after 10 min or so she needs the choke to start again also osme times you have to accelerate slowly as it kills is if you try to accellerate to fast after shes been idling for couple of min. I dont have a remote tank i was told that the carbs gravity fed and one couldnt be fitted altough i wish it could as it would save refueing on the river!

Regards Tom

 

[VicS]

Still some problems there with the carb I think.

needing a bit of choke to restart after 10 mins ?????? What I do is I turn the idle mixture knob to max richness. That gives it a rich mixture but without risk of flooding.
You try these things. If they help its good if they dont you forget them.

Not accelerating ????

I suspect the carb is not as clean as you think.
BUT
Check that the roller on the carb linkage that should be in contact with the cam on the magneto base plate is not missing. Make sure that at full throttle the butterfly in the carb opens fully.
The roller is #3 in the diagram on THIS PAGE At idle it should just be in contact with the cam and there should be a mark at that point on the cam.

It may be possible to add a remote tank. It would involve a fuel pump but that would be dependent on there being a vacuum pulse connection on the crankcase.
There would also have to be a second fuel inlet on the carb.

There is no kit listed so very likely not possible.

 

[PaulJS]

Vent?

Is there any possibility that the fuel tank vent/breather is not as open as it should be, the mention of 10 seconds delay between opening the throttle and the engine dying is what makes me suspicious.
Good luck,
Paul

 

[tom horner]

Thank you both for your help, the roller on the carb is in contact with it and opens fully at full throttle. The vent on the tank is open as far as it will allow when i undo it anti clockwise. I havent had chance to try the boat again yet it will be sunday now, i will try adjusting the carb when im out on sunday and see if it makes any difference. Its wierd as it ran fine and was just the end of the journy we stopped for ten min then started hesitating, we had been out fishing for 3 hours and stopped a few times in between and all was fine, i am not to worried about a external tank as i can fill it from a jerry can with a spout would of just been more convenient thats all, i bought the engine for £70, are they good engines from experience?

Regards Tom