1986 Evinrude Rough Idle

[irdir]

The engine is a 1986 140hp Looper and it constantly has trouble idling without it sneezing and killing itself. After a good long run it will idle longer but still will sneeze after about 3 min. of idling. If i raise the RPMs it has no problems but it won't idle at 900 RPM. I did a link and sync, checked the jetting(intermediate=16starb 20port and idle=28), and took off the carbs, cleaned them and checked the float level. I haven't checked the timing because i don't have the tools to do it without ripping the dock from its pilings but I've heard about checking it at an idle but i can't seem to find the degrees its supposed to be at. Up in NY its getting kind of cold so it's winterized but the info would help when i revive it in the Spring. It gets up to temp. and the engine runs strong otherwise.

 

[bgbass.1]

Re: 1986 Evinrude Rough Idle

check your compression had one doing the same thing ended up being the head gasket

 

[tashasdaddy]

Re: 1986 Evinrude Rough Idle

here is an easy way:

Joe Reeves
Rear Admiral

Join Date: Feb 2002
Location: Central West Florida
Posts: 4,753
Re: *ATTN: MODS* Joe Reeves WOT Timing Procedure
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The procedure I listed will work on all of the Capacitance Discharge Ignition models starting with 1973 up to BUT NOT INCLUDING the models that incorporate the Fast Start feature UNLESS one is capable of disconnecting the Fast Start feature.




quoting from Joe Reeves...

(Timing At Cranking Speed 4°)
(J. Reeves)
The full spark advance can be adjusted without have the engine running at near full throttle as follows.

To set the timing on that engine, have the s/plugs out, and have the throttle at full, set that timer base under the flywheel tight against the rubber stop on the end of the full spark timer advance stop screw (wire it against that stop if necessary).

Rig a spark tester and have the gap set to 7/16". Hook up the timing light to the #1 plug wire. Crank the engine over and set the spark advance to 4° less than what the engine calls for.

I don't know the full spark advance setting your engine calls for, but to pick a figure, say your engine calls for 28°, set the timing at 24°. The reasoning for the 4° difference is that when the engine is actually running, due to the nature of the solid state ignition componets, the engine gains the extra 4°.

If you set the engine to its true setting at cranking speed, when running it will advance beyond its limit by 4° which will set up pre-ignition causing guaranteed piston damage! You don't want that to take place.

No need to be concerned about the idle timing as that will take care of itself. The main concern is the full advance setting.

Be sure to use your own engines spark advance settings, not the one I picked out of the air here in my notes.