1986 evinrude 70 hp outboard motor

flyingscott · Jun 28, 2015

Hello my 70 hp evinrude will idle and troll really well for about 10 to 15 minutes then slows down and dies. I then have to push the high idle lever all the way forward and prime it to get it running again. good compression and spark linc and sync has been done. Any ideas

fireman57 · Jun 28, 2015

Sounds like it might be overheating. Don't run it unless you are sure it isn't.

flyingscott · Jun 28, 2015

Not overheating temp is great thermostat and water pump are new just gradually idles down till it stops

fireman57 · Jun 28, 2015

when it starts to slow down just bump the primer solenoid and it should pick back up. Is this engine new to you? Did it used to idle and troll all day? I would definitely take the carbs off and give them a good scrubbing. Make sure that your pickup tube holes are clean and the jets are cleared with a small piece of soft wire.

flyingscott · Jun 28, 2015

primer just kills it engine is new to me carbs are done all clean and clear its a tuff

fireman57 · Jun 28, 2015

If you have to push the high idle lever all the way forward and prime it then it has to be running out of fuel. Are you sure that none of your floats are sticking? When it starts to bog down squeeze the primer bulb on the fuel line several times. If it picks up then change your fuel pump. Also, are you sure that your tank is vented?

flyingscott · Jun 28, 2015

also top end is fine runs 6000 rpm with stainless 17" pitch prop

flyingscott · Jun 28, 2015

primer does nothing brand new oms pump on it and tanks are vented the ball does not flatten out at all

fireman57 · Jun 29, 2015

Earlier you said primer kills it now you say primer does nothing, which is it?

flyingscott · Jun 29, 2015

two different things primer kills it the primer ball has no effect unless unless you really get on it and then it kills it

fireman57 · Jun 29, 2015

I am still going with a stuck float or low speed jet still has some stuff in it. Did you physically remove the jets? Also did you get carb kits and clean under the welch plugs and replace them and seal them? They have a lot to do with your idle circuit, if they are not clean you don't get the proper circulation for the carbs to work correctly.

flyingscott · Jun 29, 2015

Not a stuck float if the float was stuck i should have gas running everywhere i do not it would also cause a bog don't have that. Carbs are spotless completely clean thoroughly tore down and cleaned. Its a tough problem thank you for your advice I am leaning towards the carb idle air jet is to lean or a crank seal