YAMAHA 4 degree Ignition Advancer Plate
Please check yours is a flat plate advancer
XJR1300 1999 - 2006
XJR1200 1995 - 1998
May fit early FJ1200's but please check yours has a flat plate.
Ignition advance is the number of degrees before top-dead-centre (TDC) that a spark occurs. The reason for ignition advance is that the spark to combust the fuel/air mixture needs to be timed so that the point of peak combustion pressure is when the piston is just beyond TDC.
As the speed of the engine rises, the ignition advance angle needs to increase. This is because the time to combust an unchanging air/fuel mixture is approximately constant. If the ignition advance angle were kept the same, the point of peak combustion pressure would move further and further into the combustion stroke losing more and more power. Therefore the ignition advance needs to be increased to bring the point of peak combustion to just beyond TDC.
Much better starting, improved mid range performance output and a crisper throttle responce.
If fuel quality where you live is high (e.g. UK, Western Europe, North America etc.) your bike’s standard ignition setting will not be maximising its engine’s full power potential. Fitting an ignition advancer is the easiest (and cheapest) way to improve low and mid-range torque, max power and throttle response. 2, 4 or 5-degree advancers are ideal for standard engines, for engines where the compression ratio has been raised or other physical modifications have been made, 2 degrees is the normal safe maximum.