Logo
FULL SITE MENU

1978 Johnson 55 55EL78 thermostat question

B

bryan

Member
" Yesterday was the first day

" Yesterday was the first day on the water with my first boat. Thanks to Joe Reeves and everyone that helped me on this board to get the boat in shape. My apologies to everyone at the boat ramp that had to wait while I mud wrestled with my 20' pontoon to get it back on the trailer. In retrospect I should'nt have completely submerged the bunks. I'll do better next time.
The engine did not want to idle in the water. It idles fine on the garden hose and on the warm up lever (high speed). It runs fine off of idle just about where the high speed carb circuit comes into play. I need to recheck my linkage adjustment, I think the float level needs to be raised ever so slightly and next time on the water I need to check the timing. (19*@3500 rpm minimum in gear per service manual) Unless someone can tell me how to check the timing out of the water on water ears.
I haven't verified the thermostat operation or even the presence of a thermostat. The water begins flowing as soon as the engine starts and after a hour of operation the water is still cool to the touch. Should the water from the pee tube be warm or hot? Should the water begin flowing as soon as the engine is started even when cold? "
 
"Bryan... You mentioned "I

"Bryan... You mentioned "I need to check the timing. (19*@3500 rpm minimum in gear per service manual) Unless someone can tell me how to check the timing out of the water on water ears".

And I reply....

(Timing At Cranking Speed 4°)

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 spark 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 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.

Joe (30+ Years With OMC)"
 
Thanks Joe!
This is good inf

Thanks Joe!
This is good information not found in the service manual. I do appreciate the help.
 
Back
Top