HI, I checked mine...

Left coil : FL23/600 30/2600 50V
Right : FL23/600 30/2200 50V

Figures I have two different sizes, never noticed. They both play well. The right flipper can make the ramp shot if you hit it clean and makes the orbit shot just fine... this coil has less turns (2200) which I believe translates to more power, maybe this was substituted for that purpose. The flippers are snappy for sure, but have never broken any targets with them. I did put plastic protector washers on the slingshot plastics and by the ball lock plastic as it took me over a year to find a nice replacement set for my cracked ones so I am trying to keep these safe. I put padded Firepower (1) stickers on the targets and that may be a good idea for yours, they look great and I recommend them highly.

http://www.pinballdecals.com/FirePowerTargetDecalsPage.html

My Firepower II came with a few pages called "Manual Amendment". One addresses the incorrect numbers in the original manual for the flipper coils. It says:

PURPOSE: To correct Table 4 on p. 20 and Unique Parts List on page 45.
CHANGE: Flipper part numbers
FLIPPER COIL. Firepower II pinball uses 50-volt flipper coils.
Please correct your solenoid chart (Table 4) on page 20 of the
FIREPOWER II service manual to show part number FL23/600 30/2200 50V
for both flipper coils.

The number now shown in the book must NEVER be substituted for the
new 50-volt flipper coil, or game damage may result.

NEW ASSEMBLY NUMBERS. WILLIAMS has also updated the flipper
assembly numbers. Please correct your book on page 45: The left
flipper assembly should be C-9953-L, and the right flipper assembly
should be C-9652-R.

I hope this helps! There is another amendment that addresses some changes on page 10 Game Operation and Table 2. Game Adjustments. Basically it adds functions 36 and 37 which deal with extra ball difficulty and the bell ringing for bonus holdover (or not). I can type it in verbatim if anyone wants it.

I am a newbie to this forum. I have been fixing up an old Firepower II, and like most others am looking for parts. In particular (besides a fully restored playfield!) I would like one of the upper pop bumper plastic tops. I also just finished changing all the bulbs out to leds from cointaker. It looks SO MUCH nicer. I used red bulbs under the red inserts, green under the green, etc. As a change, I put blue leds under the 50-100-150 inserts below the ball release target and the 10,000-20,000-50,000 inserts below the ball lock. It really adds a nice touch.

Welcome, thanks for the flipper coil info and yes please to the other amendment! If you can scan or take photos of the amendments you have and attach them as images, I'm sure many would appreciate it.
Have fun with your game

My game has a sticker on the playfield that states to use FL23/600 30/2600 50v - no mention of 2200. So not sure what’s correct after reading that service bulletin. This game was a German export.

CC822305-DD03-4624-B54C-C2E6F029ACEA (resized).jpeg

15B8FCF4-99E6-4E57-B114-5C6A96F8CED2 (resized).jpeg

Would've been nice if he had posted that addendum...