How do I tell if my engine is misfiring? What does it sound like? How can I tell?

My engine's idle is eratic. It varies from 1000 to 1300 RPM (1100 is normal for an R1). It sounds "a bit rough" but when you rev it it seems fine. It failed emissions at SVA yesterday with high hydrocarbons (500ppm or more) but low CO. This was with me adjusting the mixture from rich to lean. Someone suggested it might be misfiring but I don't know haow to tell.

sounds anything from the odd pop while running at a constant speed to a machine gun like effect!

Do you have a low and high ldle adjustment??

If its running ok above idle, doubt its misfiring! More like blocked something or other thats controls idling

Ask in the bec section! even though i building a bec all my tunning experience is on car setups and heavy diesels!

Anyone got a rough 1000hp caterpillar

It has an idle adjust screw which is just a stop on the throttle that stops the butterflies closing fully.

It doesn't make any poping or machine gun noises. The idle noise is not rhythmic or even but the pulses in the noise are irregular, sometimes bunched up, sometimes with a slight gap.

A "normal" engine would make the sound duh-duh-duh-duh-duh-duh-duh-duh with a frequency of about 8 times a second.

Mine goes duh-duh-DUH-duh-duh-duh-duh-DUH-duh-duh-DUH-duh-DUH