Mounting using the pilot hole

By far the easiest way to fix your trigger wheel is to use one of the wheels with a pilot hole. This hole can be drilled out, if necessary, to suit your crank bolt, which will then hold it perfectly centered. If your front pulley is dished then you should use a spacer behind the pulley and a longer bolt to compensate for the additional thickness. The spacer could be as simple as a pile of washers, a piece of thick-walled pipe of slightly larger diameter than your bolt, a piece of ali/steel bar with a hole drilled through it or machined on a lathe. We now stock 5mm thick spacers to suit our trigger wheels, these are available in 50 and 75mm diameters and as a mult-thickness shim kit. To use these simply stack up the appropriate number to either sit level with or just proud of the front face of the pulley.

Once you have your wheel centered on the pulley and spaced out correctly you need to rotate it so that the missing tooth is in the correct position relative to the sensor. On most 4-cylinder engines this is 90 degrees BTDC (Before Top Dead Center), on V6 engines 60 degrees BTDC and on V8 engines 50 degrees BTDC but please check with your ECU supplier as what they expect does vary. When correctly oriented you should secure it in place with either a small bolt/set screw or a roll pin, this will stop it from rotating as you tighten up the main crank bolt.

The pulley onto which we are fitting the trigger wheel.  Note the  three convenient bolt holes.	The trigger wheel as supplied
The pilot hole has been drilled out to fit central bolt, 16mm in this case	FA stack of 50mm diameter spacers fitted, the pilot holes on these were also drilled to 16mm
Trigger wheel mounted and spaced out	Finally an M8 bolt is fitted to prevent the wheel from rotating