Chirping under load

So I checked the valve shims, all within spec, put the engine back together. All straight forward, no issues other than I originally forgot to tighten the clamps holding the TB's on, did that at 11:30pm last night.

So now it chirps/rings under light-moderate load. I specify load because the throttle position at which it happens varies per rpm. Low rpm, it may only require 1/4 throttle to make it chirp/ring, higher rpm requires 1/2 or more. Considering it happens at any rpm, that tells me it's not vibration.

Also, if I turn the throttle past the chirping, it stops...until the rpm rises to a point that it's at that load value again and the noise starts anew.

Is that what knock sounds like in these engines? It's not the marble-like sound I'm used to hearing, but the fact it occurs only under light-moderate load has me concerned it might be. It's not the whirring I posted a video of, previously; it's a definite chirping noise.

It made it to work just fine, 47-ish iles. I'll ride it home just the same. I'll pull the airbox apart tonight and see if anything stands out as being 'wrong', but if anyone has ideas in the meantime, I'm all ears.

Noticed last night that my airbox isn't perfectly lined up with the head, on the rear. There's about a 1/16" lip. I didn't correct it yet, as I was busier with other things. Could this be causing a whistle? If it's only whistling during intake stroke, that could be the 'chirp' I hear.

Brainstorming

Will fix it in the next day or two and see if that cures it. Teaching the wife 3D drafting in the evenings, she wants a career change.

Brought the airbox into better alignment with the head. Also double and triple checked all my hose connections and port caps. Everything is solid.

My whistle is now worse.

Can you make a short video so we can hear it ? It might be help full.

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Originally Posted by EBRRider

Can you make a short video so we can hear it ? It might be help full.

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I need to buy some double sided tape for my camera mount first, but I intend on it.

Wife said yesterday, "Your bike doesn't sound like other bikes on the road. When you're just cruising, it has this weird whine. When you're flying by with the front in the air, it sounds like a beast." Then she proceeded to scold me about 80mph wheelies next to the car with my daughter watching. lol

Oops! Is that where my son learned that from!!

Hard to hear, I'll try to get better video from home instead of my commute. There's a couple whistles in there, though.

https://www.youtube.com/watch?v=3kr8XIalpUs

All I hear is your hairdryer?:)

Get a pipe and you wont hear anything but motor music.

https://www.youtube.com/watch?v=pHoKD-sLl-w

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Originally Posted by Cooter

All I hear is your hairdryer?:)

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Quote:

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Originally Posted by EBRRider

Get a pipe and you wont hear anything but motor music.

https://www.youtube.com/watch?v=pHoKD-sLl-w

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Funny guys. lol

I was talking with Geoff May today on the phone and he asked if I'd used any kind of grease when working the throttle bodies back in. I hadn't. He said that could've bent the rubber too far and caused a tear or crack in one of the boots. He explained that on the race bikes, they used a touch of bearing grease, just enough so the TB's could slide in, not so much that any would goop up in the intake tract.

Good idea as any. Now I get to tear it apart again. Need more beer for this.

Cheers! You'll still have the noise, but you just won't care anymore:nut:

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Originally Posted by Cooter

Cheers! You'll still have the noise, but you just won't care anymore:nut:

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Hah, yeah. Been riding it consistently. It tends to have some hot start issues, but I'm looking at other causes for that...evap purge valve and will clean/tighten frame grounds.