Motor firing opposite direction

[TannerN]

8 minutes ago, oldjeep said:

Now you need to have the dealer set the final timing, unless you have diacom.  You can't set timing on a computer controlled vortec with a timing. Light.  You need to be able to read the cam angle. 

Thank you.  Will do

[oldjeep]

And just for information sake - if you do have access to a Diacom (MEFI scanner), this is the procedure from the Indmar manual - this is for MEFI-6 (2011 +) but I believe that the procedure is the same for MEFI-5, since it is the same procedure you use for a 5.7 Vortec in a truck. (with an OBD2 scanner)

Camshaft Retard Offset Adjustment
(5.0L and 5.7L)
Test Procedure
The ignition timing is not adjustable. The distributor
may need to adjusted in order to prevent ignition
crossfire. To insure proper alignment of the distributor,
perform the following:
Note: The scan tool Cam Angle reading will not be accurate below 1,200 RPM.

1. Engine idling at operating temperature. Observe the scan tool Cam Angle parameter.
2. Increase the engine speed to 1,200 RPM. Verify the scan tool Cam Angle parameter is within 685–725 degrees.
⇒ If within the specified value, the distributor is properly adjusted.
⇒ If not within the specified value, adjust the distributor.

Adjustment Procedure
1. Ignition OFF, slightly loosen the distributor hold down bolt.
Note: The Cam Angle reading will not be accurate below 1,200 RPM.
2. Engine operating, raise the engine speed to 1,200 RPM. Observe the scan tool Cam Angle
parameter.
⇒ If the Cam Angle parameter is less than 685 degrees, rotate the distributor in a counterclockwise direction to adjust.
⇒ If the Cam Angle parameter is greater than 725 degrees, rotate the distributor in a clockwise direction to adjust.
3. Repeat step 2 until 705 degrees is obtained.
4. Ignition OFF.
Caution: Use the correct fastener in the correct
location. Replacement fasteners must be the correct
part number for that application. Do not use paints,
lubricants, or corrosion inhibitors on fasteners, or
fastener joint surfaces, unless specified. These
coatings affect fastener torque and joint clamping
force and may damage the fastener. Use the correct
tightening sequence and specifications when installing
fasteners in order to avoid damage to parts and
systems. When using fasteners that are threaded
directly into plastic, use extreme care not to strip the
mating plastic part(s). Use hand tools only, and do not
use any kind of impact or power tools. Fastener should
be hand tightened, fully seated, and not stripped.

5. Tighten the distributor hold-down bolt.
Tighten
Tighten the bolt to 27 N·m (20 lb ft).

Engine Controls and Fuel - Marine 9-255
2011 -

Edited January 24, 2018 by oldjeep