Adapting an FCS ring wrench for the Montreal

Tom Sanor ("Mr Goose")

The photo shows a SPICA Fuel Cutoff Solenoid tool I recently made. The advantage of this tool over normal methods of unscrewing the locking ring is that it can be used with the air filter box in place. I felt this was beneficial in getting the correct air/fuel ratio since the setting is normally made with the engine running at around 2500 rpm. (During dyno tests I saw that the engine develops more torque with the airbox in place than with it removed. That's the air horns' effect, and good Alfa design.)

The tool I made is used with a standard 3/8" square drive socket set (however the drive hole could be made any convenient size). The tubular body was turned on a lathe, and the sizes, which can be varied somewhat, are around 30mm i.d., 35mm o.d., and 44.5 to 50.8mm length. Make trial fits on your car before finishing. Mine was made "stepped" due to the piece of tubing I had on hand.

On one end was MIG-welded the drive plate with square hole, and on the other the appropriate internally-toothed ring wrench. I bought the square-hole plate from SEARS ( and it is their part no. 44191 "Speeder Disc Set" which costs USD 5.29. The ring wrench originally had a handle on it which was sawn off, saving only the circular part. This is part no. 41109 "Solenoid Wrench" available from AR RICAMBI ( for the steep price of USD 40.00.

After welding, a bevel was ground off the small end, which is necessary to slip the tool past the thermostat housing. One must also disconnect the wire lead on the end of the FCS while the tool is in use.

Now I can easily loosen and tighten the ring nut using a 3/8" drive socket wrench, extension, and flex joint, which then permits hand adjustment of the FCS while the engine is running.

return to the Alfa Romeo Montreal Spica FCS section