I stumbled on this today and it seems it was a ‘to-do’ mod for the SV650 in US and UK race series, but the stock Suzuki woodruff key part number 09420-04008 is used a huge number of Suzuki bikes including the DL650 & DL1000 V-Strom, DRZ250 and DRZ400, the DR250, DR650, DR800 BIG and a large number of Suzuki road bikes.
A Woodruff key is embedded in a slot in the crankshaft and locks the flywheel in place on the crankshaft. On the outside of the flywheel the triggers for the ignition are located. By fitting an offset key the ignition timing is advanced by however many degrees the key is offset for.
Removing the Woodruff key
I found a number of references to SV650 owners getting a noticable mid range improvement after fitting a 4 degree advance offset woodruff key but couldn’t find any references to anyone having done it to a DR650 or V Strom, though there is a guy on Facebook that sells a electronic ignition advance unit for the DR650 which he claims makes a difference though he hasn’t quantified in any way how much of a difference, that costs $470 Australian.
I’ve attached instructions I found elsewhere online on how to do this mod if you have an offset woodruff key, the instructions are for a sv650 but would look the same for most Suzuki’s.
So an obvious question would be , where do we get an offset key from?