My WD M20 is currently running a 16 tooth sprocket on the engine drive and an 18 tooth sprocket on the gear box drive. The bike feels a little under powered in top gear. Could any one recommend what I could do to get a bit better cruising speed please.
My BSA book says 18 teeth for M20 and 20 teeth for M21, I believe it wish to add a extra tooth to suit modern roads conditions. I hope this helps.
Richard
Your setup should not feel underpowered.
I run a 19T engine sprocket and 18 gear sprocket,
And MY WM20 pulls a heavy metal sidecar, sometimes with 3 persons.
I cannot do wheelies, but it pulls even uphills.
Can it be you replacing the feeling of too short gears with underpower?
If your ignition is set up fine and your carb is good and jetted correctly,
And the compression is good and head gasket is sealing,
I would try to change the engine sprocket to 19T and see what happens..
