Carryout these tests with engine off.

Remove air filter or cowling from air filter system ensuring that all fixings are away from the engine and not stored in any filter or cowling parts. Replace your air filter at the earliest point after these procedures are complete.

Idle (Static)
Loosen locknut and adjust Idle Screw 1 (Fig.1) so that the crescents in the right-hand roller (as seen from the outside of the engine)are open approximately 1mm (Fig.2) and retighten locknut.

Balance
Loosen locknut on Balance Screw 2 (Fig.1) and adjust left-hand roller so that the crescents match those of the right hand roller. Retighten locknut.

Fig. 1
Viewed from the engine

Full Throttle Stop (Rollers)
Ensure that the barrels reach full throttle. Loosen locknut and adjust with Full Throttle Stop Screw 3 (Fig.1). Adjust so that the average of the rollers is fully open. (Fig. 3) Due to manufacturing tolerances it is normal for slight difference in the amount that the rollers appear to open.

Full Throttle (Cable)
Check that full throttle is achieved with the cable adjustment as per the cable set up of your car. Ensure that the rollers are fully open and reach the Full Throttle Stop. This is best done with a second person sat in the car.

Full Throttle Stop (Pedal)
When all preferences for throttle pedal adjustment are complete it is essential that there is a stop for the pedal so that the roller mechanism and cable are not strained. If there is not one fitted to your car contact the supplier or fabricate one.

Fig. 2

Dynamic Idle (Engine Running)

Check that the throttle cable is free running, not caught on any linkage parts and that both rollers are at the idle position (Fig.1) Start engine and warm up to running temperature. Loosen locknut and adjust Idle Screw 1 (Fig.1) so that an engine idle speed of 1000rpm ± 50rpm and retighten locknut.

Using an Air Flow Meter, (Fig.3) the flow rate through the rollers can be measured more accurately and will achieve a smoother running engine. Loosen locknut on Balance Screw 2 (Fig.1) and adjust so that the average readings from each roller on the flow meter are the same for each roller. Retighten locknut. Re set Dynamic idle as above.

Fig. 3