'87 740 GLE ignition timing

[jimmy57]

The first thing is to check that the balancer where the mark is located has moved. You have to have help. Have a trusted helper hold a crew driver down into the first spark plug hole. Now turn engine with 1/2 ratchet or breaker bar until it stops. Mark balancer where 0 mark is at the balancer ring. WIth trusted helper holding the screwdriver EXACTLY in the same position turn the engine reverse until it stops, mark at 0 there. Helper can turn loose and remove screw driver. The notch on balancer will be exactly between the marks if it has not slipped. If not then make a mark halfway between marks to use this one time. If the timing mark bounces around while you're shooting light at it then the throttle switch is not actually closing and needs to be fixed.

[jimmy57]

Yes, left is BTDC and right heads toward ATDC