89 Force 150 Spark Plug number???

[VIP FORCE]

I have a 1989 Mercury Force 150 outboard and am looking to verify the NGK spark plug number. I just purchased a Seloc Force outboard service manual and believe it or not it does not list a 150 engine in 89 under the tune up section!!! I dont want to match up the current plug because I just bought the boat and my luck it could be wrong...
any help much appreciated..

[maxum247]

If your 89 Force 150 is the "A" series my manual say's this.

From my Clymer manual: 1989-1991A 150hp. Force outboard with (Prestolite CD Ignition). (Blue Coils, Blue CD Modules) uses Champion Spark Plug no. UL18V.