Spark advancing as RPMs rise

[aw113sgte]

Hall sensor. No sync errors at all.
Motorcycle COP, 11500 max RPM
"dumb" coil, driven by 873 driver. Fired at "going high"
Running fixed timing 10 degrees

I tried changing the rising/falling edge on the the Hall, no change in advance.
I was running 3ms dwell. As I lowered the dwell (down to 1.0ms) the advancing became less and the timing light showed less deviation in the timing. The timing is showing rock solid 10 degrees at idle with the 1.0ms dwell. Spark duration is still at 0.9ms
It is still advancing at 1.0ms but the software won't let me lower it any more so I'm wondering if there is something else I should look into?

[billr]

A few questions:

What kind of coil?
How much is the spark advancing?
Are you sure it is advancing and not retarding?
Have you played with "spark latency" at all (usually a cure for retarding, hence the question above)?

It never hurts to post the MSQ file...

[aw113sgte]

A few questions:

What kind of coil?
How much is the spark advancing?
Are you sure it is advancing and not retarding?
Have you played with "spark latency" at all (usually a cure for retarding, hence the question above)?

It never hurts to post the MSQ file...

I'm not sure what specifics on the coil you need. It's COP, no logic in it (2 wire). It's the stock COP for this motorcycle.
Advancing to about 20 degrees BTDC by 8000 RPM
Yes it's advancing. Have the marks on the degree wheel.
No, haven't touched it.

wr250x 7-26-15.msq

[billr]

On the coil, brand and P/N. Honestly, I probably can't help with a motorcycle coil, but somebody who can will need to know precisely what you are working with. Generally speaking, spark and dwell times should have no effect on timing; there should be plenty of time in a "spark event cycle" for both of those when set to proper values.

[aw113sgte]

On the coil, brand and P/N. Honestly, I probably can't help with a motorcycle coil, but somebody who can will need to know precisely what you are working with. Generally speaking, spark and dwell times should have no effect on timing; there should be plenty of time in a "spark event cycle" for both of those when set to proper values.

Hmm wonder if it could be how the timing light is displaying it. When I change the dwell (can do this while the engine is running) at idle it get more erratic and advanced the larger the number.

[elaw]

Advancing with RPM almost always means the spark output polarity is wrong. Try the opposite setting. If that fixes it, you'll also have to recalibrate your timing.

[racingmini_mtl]

Put a light bulb in place of your coil. If the light goes on when you turn on the power (don't crank), your output polarity is wrong.

Jean

[aw113sgte]

I just tested the coil plug. No current flowing when ignition on but not cranking. Current does flow when cranking. Sounds like polarity is correct.
I retested and verified it is firing 20 degrees BTDC when at higher rpm, but 10 at idle.

[billr]

I should have asked before... are you using a reliable (simple) timing light, or one of those dial-back ones that are always questionable?

[aw113sgte]

I should have asked before... are you using a reliable (simple) timing light, or one of those dial-back ones that are always questionable?

This one: http://www.amazon.com/INNOVA-3551-Induc ... B000EVYH72