knock - tuning ignition timing - 150cc engine motorcycle

hi,

I watched your video and i think your saying in tuning ignition timing on the street, you going to listen the knock. with knocking sensor and so on..

But I do experience differently. I tuned an small engine that doesn't have knocking but it needs to adjust the ignition timing lower to have more power. I think the compression ratio is slow that's why there is no knock? or I just haven't heard of the knock?

By the way.. I am from Philippines, and we are mostly motorcycle here. 150cc-200cc motorcycle engine.

Not all engine can actually knock from ignition timing being too much advanced. In the course here, it's referred as an engine which is not knock limited.

When you tune ignition timing, you start with low advance and slowly add timing, until a) you hear knock or b) you get to the peak power (which is called MBT, minimum timing for best torque). If you keep adding timing pass the MBT point, you will see that the power will stay the same for a couple of ignition advance, and then will fall out, lower the torque output of the engine. Maybe you are in this situation.

Tuning timing is way much easier to do on a dyno, because you can see the torque output of the engine in real time. On the street, you could use a time slip from a 1/4 mile drag, but you would need a super consistent driver as well.

Hi,

Thank you for the response... yeah So for the street, can I use the speed to put into the datalogger and put into the table of ignition timing? so that i will know what speed on that specific rpm... is that ideal todo?