1986 Evinrude 40hp idling problem "I'm done with it"

[digger658]

After wrestling with the idle problem on this motor for quite some times I took it to a mechanic. He said the problem could be a cracked ring which would not allow the piston to draw enough gas through the carbrator and making it run lean.

I had the compression check twice and both times had 130 psi on each cylinders. This motor run excellent at top end. Does this sound right?

 

[Daviet]

Re: 1986 Evinrude 40hp idling problem "I'm done with it"

I guess anything is possiable.
What have you tried to correct the problem?
Have you overhauled the carbs, are the idle orifices the correct ones for your engine?
What idle speed are you running at?
What shape are the plugs in and are they the correct ones and gapped properly?
Have you checked spark with a timing light at idle, do you have a constant flash on each plug wire?

 

[fireman57]

Re: 1986 Evinrude 40hp idling problem "I'm done with it"

It is not a big job at all to pull the head on this engine and inspect the cylinders. You are only out the cost of a head gasket but I agree with Daviet, if you haven't cleaned/rebuilt the carbs that is the first thing I would do. Shouldn't take you more than an hour and a half. Sounds like he wants the money for a rebuild job instead of a carb rebuild job.

 

[digger658]

Re: 1986 Evinrude 40hp idling problem "I'm done with it"

I guess anything is possiable.
What have you tried to correct the problem? Have you overhauled the carbs, are the idle orifices the correct ones for your engine? What idle speed are you running at? What shape are the plugs in and are they the correct ones and gapped properly?
Have you checked spark with a timing light at idle, do you have a constant flash on each plug wire?

Rebuild carbs/replace vro with new pump/new plugs and coils
Orifices I believe they are original
At one time had to adjust idle high to keep it running, this made the gears grind when putting it in gear.
Yes the right plugs set at .030"
Spark jumps 5/8"

 

[fireman57]

Re: 1986 Evinrude 40hp idling problem "I'm done with it"

When you pull the spark plugs are they wet or dry?

 

[rshiver]

Re: 1986 Evinrude 40hp idling problem "I'm done with it"

I was having the same problem as you're talking about, checked my reed valves and had 4 bad ones...just sayin