1968 Merc 500 - spark advance stop screw out all the way

[mike_ct]

been running it a few times like this, just noticed its out all the way, and the distributor not contacting the stop when w.o.t., runs great, my concern is i'm in the danger zone and may have too much spark advance at w.o.t.

question is, with type ii/lightening energizer distributor, is the only way to check max advance with a tach + timing light -> motor in water?

can i get a timing reading if i pull the plugs + fuel, tank the motor, advance throttle to w.o.t. and use starter and read timing with light or does it have to be actual w.o.t. rpm?

 

[usskydvr]

Re: 1968 Merc 500 - spark advance stop screw out all the way

What I do if I don't have a timing light handy is close to what you had planned. You don't even need to tank the motor. Pull the plugs. Leave #1connected to the ignition wire and ground the housing. Pull the coil wire, but leave it close so the gap can be jumped by the spark. Go to full throttle, check to see that the dist is at the WOT spark advance stop. Turn the ignition on and slowly rotate the flywheel. As you do you will hear the spark jump at the disconnected coil. When you do this for the #1 plug just look where the #1 marking on the flywheel is in relation to the timing tape/marks.

 

[Car Guy Buys Boat]

Re: 1968 Merc 500 - spark advance stop screw out all the way

Better make sure there is no centrifugal advance to trip you up on the slow rotation method.

 

[usskydvr]

Re: 1968 Merc 500 - spark advance stop screw out all the way

There is no centrifugal advance on that motor.