Stupid tune up question

BKS72

Petty Officer 3rd Class
Joined
Sep 5, 2008
Messages
99
To check timing advance , I need to be able to run my motor (1980 E'rude 75) at 5200 RPM in gear. I don't have a test wheel and don't think it's safe to be fooling with the timing light while running up river with the flywheel exposed:D Can I do this with it on the trailer (I don't think I can get the RPMs high enough and if I can, I don't know if it would be bad for the motor). Any suggestions? Like I said, stupid question, but if I don't ask I'll never know......Thank you!

Branden
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Stupid tune up question

You can check the timing on that model as follows.

(Timing At Cranking Speed 4?)
(J. Reeves)

NOTE: If your engine has the "Fast Start" feature", you must disconnect/eliminate that feature in order to use the following method. The "Fast Start" automatically advances the spark electronically when the engine first starts, dropping it to normal when the engine reaches a certain temperture.

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
 

BKS72

Petty Officer 3rd Class
Joined
Sep 5, 2008
Messages
99
Re: Stupid tune up question

Thank you! I never would have found that info in a million years without this site! .

I've been reading through the factory manual sync procedures and it looks fairly straightforward and relatively easy, but I've been scratching my head over how I was going to check that spark advance.
 
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