View Full Version : Coupler install per Merc bulletin

06-07-2011, 07:39 PM
Not a big deal but sometimes the little things help.

My service manual on the 502 doesn't have the updated procedure but I found the service bulletin and followed it.

This already assumes you have the motor out and the old coupler removed.

1. Check runout on the flywheel. Install a dial indicator on the side edge of the teeth of the flywheel. Pic 1

2. Good to have a second pair of hands for this one.... Rotate the engine 360 degrees, checking the runout as you go. Should be no more than .008 in. max. Mine was .002 max.

06-07-2011, 07:44 PM
3. Obtain 3 tapered head screws from you local hardware store. 3/8-16 x 3/4. I need to get 1-1/4" long screws for the 502 flywheel. Wasn't enough thread on the 3/4" ones.

4. Install the 3 screws in every other hole and snug them tight. This is the change from the manual. The tapered head screws insure the coupler is centered over the flywheel hole.

06-07-2011, 07:47 PM
5. Install 3 of the six permanent machine screws with loctite or equivalent.

6. Torque the 3 to 35 lb-ft.

06-07-2011, 07:49 PM
7. Remove the 3 temp screws and install the last 3 permanent screws per steps 5 and 6.

06-07-2011, 07:52 PM
8. Prime and paint if your as anal as I am.:wink:

Service bulletin is No. 2009-11