avramd

Hey Everyone,

Long time no hear ;-) The weather's getting nice, I'd love to see a 3d graph of tech forum post frequency vs. date vs. latitude...

Short story: My hawk makes a very distinct "tick" sound that happens exactly every other revolution. The volume of this click seems to be constant. The only variation is the frequency, which is exactly proportional to RPMS (1:2).

Here's a little audio clip. It is 2.48 secs clip of my engine running at about 1500 rpms. The click happens 30. I slowed it down in an audio editor, and it stands out very clearly every 0.077 secs, which means every other rev at 1558 rpm.

I have read on the forums that it is normal to hear clicks associated with the carb sliders. I think this is not that because I'm pretty sure I know what those are, and they are (correct me if I'm wrong)...

• more of a clatter than a consistent click
• louder than this
• they don't always happen (or you can't always hear them), depending on engine temperature, load and throttle position.
• I would expect them to happen twice per revolution, not once every other rev, right?

I admit I haven't used my hawk since December-ish, so maybe these were always there and I didn't notice them. However that doesn't necessarily mean they are legit. Also I just re-seated my exhaust pipes and installed a gasket in one of them that was missing before - the pipe was clamped onto the flange so it didn't sound that loud - but it's quieter now, so maybe that's why I'm noticing this.

If I had to describe the sound itself, it actually sounds like a spark somewhere, like as if some high voltage wire has a break in its shielding, and it's arcing somewhere that I can't see.

Does anyone have any ideas what this might be, and if it's normal or how to fix it? I wouldn't say that it is a problem by itself, I just wonder if it is warning me about a problem.

RCVTR

Take a piece of hose and put one end up to your ear and move the other to suspect locations until you find the source of the noise.