Timing marks on fly wheel.

[sailorboi]

Hey y'all,

I recently bought a 1979 starcraft with a 1974 55hp 557HG Chrysler outboard (Alternator version). The previous owner messed with the timing on the ignition, I got it to start after properly gapping the contacts under the flywheel and eye balling the timing with a multimeter and a chopstick in top cylinder.

I'm going to time it with a timing light gun and degree wheel this weekend and I hope someone could answer a few questions for me.

1. Are the marks on the flywheel for TDC or BTDC?

2. What degree offsets am I aming for idle and WOT?

3.What are the two marks on the ignition plate how do I set a base line before adjusting it?

 

[Nordin]

There should be two marks at the flywheel.
One is 36 dgr BTDC and the other is 0 drg (TDC) for top cylinder.
Are there only two marks at the ignition plat/flag?
There should be three, one longer and two short at the right and left of the long one.
The long is zero and the left one is +2 dgr and the right one is -2 dgr.
When you line up the long with 0 mark at flywheel it is TDC and the other two are (-)2 dgr ATDC and (+)2 dgr BTDC reference to 0 mark.
I would suggest you to set the timing 28-30 dgr BTDC at WOT.
30 dgr BTDC is just a bit (add double distance as between long mark and -2 mark) to the right of -2 line at ignition plat/flag reference to 36 dgr mark
You do not set timing at idle at these engines.
It will be what it will be when you have adjusted the idle at the idle screw and the air/fuel mix screw.