I took a all stock KX500 engine with the ignition marks on the middle position.
I ran it on the dyno and ran it at 53.11 HP.
Then I ran the Power D at .087" BTDC and lost a full 2 HP.
Part of the power loss is likely due to the lighting coil on the Power D.
Referring back to a conversation with Ben Probst on his experimentation with the KX500 I decided to see where his recommended numbers were on the Power D.
As discussed earlier he runs .094" BTDC.
So how many degrees of advance is .094" from .087"?
Approximately .663 degrees.
If you want to check my math, go for it
From previous testing we lost 1 HP for every 1 degree of timing retardation.
So I thought Ben's numbers would be higher but surprise, it's not.
The next question is, how much more HP can we gain back?
Also, how much do I need to move the piston before TDC to gain 1 full degree of ignition timing?
Next, how much do I need to move the piston from TDC to gain 2 degrees of ignition timing?
And last, will a all stock KX500 engine let me run the ignition at 2 degrees advanced without negative effects?
- Ignition timing.png (41.81 KiB) Viewed 2853 times