Now the motor hesitates

[da83moon]

1979 evinrude 55 HP

Well gotten everything Back together again. However now the engine hesitates from idle to wot. I've went through the linc and sync and now ideas now. Carbs are clean (replaced the top carb all together with a factory one).. check.. replaced all the gas lines...check... link and synced and all carbs are running great check. MY problem lies from idle to midpower. I have to fast start it to get it started sometimes and then when it gets running good. Can shfit it and it starts to die and then when I get it over half catched and boy do we go. Heres what I had to replace: I had to pix the powerhead to exhaust plate, the thermostat, for good measure, the head gasket for even more safe measure, the top carb because the jet was stripped out and I was was tired of tinkering with it becuase it was sucking at idle. So any ideas, workings to do would greatly help. The copression is 150 top 145 bottom.

 

[Lone Duck]

Re: Now the motor hesitates

1979 evinrude 55 HP

Well gotten everything Back together again. However now the engine hesitates from idle to wot. I've went through the linc and sync and now ideas now. Carbs are clean (replaced the top carb all together with a factory one).. check.. replaced all the gas lines...check... link and synced and all carbs are running great check. MY problem lies from idle to midpower. I have to fast start it to get it started sometimes and then when it gets running good. Can shfit it and it starts to die and then when I get it over half catched and boy do we go. Heres what I had to replace: I had to pix the powerhead to exhaust plate, the thermostat, for good measure, the head gasket for even more safe measure, the top carb because the jet was stripped out and I was was tired of tinkering with it becuase it was sucking at idle. So any ideas, workings to do would greatly help. The copression is 150 top 145 bottom.

Try opening Idle mix screws 1/8 of a turn . Also , how is your fuel pump. and anti siphon valve?

 

[5150abf]

Re: Now the motor hesitates

I would look at the mid jet in the lower carb, yes you cleaned but it isn't clean, be sure to run a wire and compressed air through the passage between the idle and mid jet.

I don't have a compressor so I use the air in a can that is for blowing out your computer, works well.

Had the same problem on my 50, cleaned the carbs twice still had the stumble just off idle until I cleaned the passage between the jets.

You have air and ignition so it almost has to be a fuel issue.

I have a dental syringe with a plastic tip that I use to find which carb isn't giving gas, a little squirt of fuel will either make it stumble or take off, makes it easy to find the offending carb with out having to pull them all.

And I am sure you know this but your motor doesn't have an idle adjustment screw, only jets.

 

[jtexas]

Re: Now the motor hesitates

Sounds kind of like a carb/timing issue -- recheck the pick-up timing, make sure the timer base moves smoothly without sticking, doublecheck your idle speed.

 

[da83moon]

Re: Now the motor hesitates

Thanks all who have answered. Is the pick up timing the timing that you use the timing light on?

 

[david_r]

Re: Now the motor hesitates

sorry i dont know the terminology for all the parts but



you dont by chance have the carb roller thing touching the cam do you?

you dont want the carb to start to open until you have a little timing advance........a little goes a long way.

i did a link and sync on mine a while back and i had the carb roller too close to the cam and it started the fuel flow before it had advanced timing...........it isnt by chance trying to spit and die is it?

 

[da83moon]

Re: Now the motor hesitates

It is the throttle cam roller. That is what I screwed out to have it match the part on the carb becasue there is a little plasctic roller type thing that i thought was suppose to touch the throttle cam roller and always be between the little notches on the throtle roller is this wrong?

 

[tashasdaddy]

Re: Now the motor hesitates

do you have the OEM Evinrude manual for your specific motor?

 

[da83moon]

Re: Now the motor hesitates

Unfortunatly its the seloc, at the time before reading this I thought this was a good one to get.

 

[jtexas]

Re: Now the motor hesitates

pick-up timing means the timing at the point where the roller hits the cam -- but david's right, if the cam hits the roller too soon, it'll hesitate, maybe die out altogether instead of accelerating. You want the roller to hit the cam on the mark.

this is a 3-cyl, but you should have the same parts, mostly:

If that plastic fitting holding the throttle-timerbase link rod in place ever breaks, you'll get some real strange symptoms, similar to what you described. Don't ask me how I know.