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Discussion Starter #1
I did a search but didn't see anything so I thought I'd ask...

New VT750C8 (Aero 2008), 550 miles on it.

Today, after a long ride on a hot day, I stopped with some workers at a bar (no I don't drink at all) for some face time. Chatted it up for a few hours then went to ride home.

I noticed that at idle, and any time the engine isn't under load (accelerating), that there is a small whistle or even 'tap on metal' high pitch sound with the firing of the cylinder (just after). So like 'lug whistle, lug whistle'.. etc... I proceeded home. I noticed that under acceleration this goes away, but even cruising at a stable speed (40 for example), it's still there. Enough so that you can even hear it over the wind and exhaust (though all stock still so it's not overly loud).

Is that the valves that they say need to be tweaked at 600 miles, an intake flap of somekind, anything come to mind? This only started today after that long (but relatively fluctuating country speeds) ride.

On another note, it was in the shop for another rattle type sound (very similar to the exhaust covers, though I held my foot on them and it would still do it so I think I eliminated those as the source) that I could most easily get to occur repeatedly from 0-25 in first gear at a medium hard pull. Right when it went through 20-25 MPH, you'd just hear a little 'ring' just for a split second. It would occasionally do it again usually in 3rd, again under a medium to harder acceleration pull (have yet to do a full twist pull though, still breaking it in...)

Are the two related? Any ideas? The new one with the engine firing is really annoying me. The other one I can overlook if it's more of jsut a normal sound.
 

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First thought:

Check to make sure your spark plugs are tight. If the factory didn't torque them properly they may have loosened enough to allow a small squeak of compression to escape. I'd pull the plugs and inspect them, then reinstall them to the proper torque.

This may not be the issue, but at the very least you'll get to see how your plugs are burning.

-- Mark
 

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Have you ever owned a Shadow before, or even a Honda?

I'm wondering if that sound you're hearing is the cam chains. Almost every Honda makes it, and it's the sound that the valve train makes, which is a sound that it's supposed to make.

Not saying that it's the sound you're hearing, but when i got my first Honda, there were a lot of noises that I thought were' not normal. When I got to taking it apart, it turns out that these noises are part of its engineering and the reason I hadn't heard it on other bikes is because they weren't designed the same way. It was my first bike with overhead cams!

--Justin
 

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Now that I think about it, mine has the same whistling noise as well. It's actually more of a whine similar to a supercharger. I never really minded it.

Hopefully it is normal...
 

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Discussion Starter #5
It wasn't there before... This isn't just a small whistle... This is a pretty obvious one. Enough it's irritating. And it goes away under load. A cam noise wouldn't. It just happened the last 20 miles or so... The last time I started the bike. Other than that it hasn't been there.

No, it is not the supercharger type whistle that I hear also. That I know is just the intake noise. This one is more of a high pitched metal scraping on metal than a whistle. And louder than the firing of the cylinder and immediately following, only when not under load.
 

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Discussion Starter #6
Notorious said:
First thought:

Check to make sure your spark plugs are tight. If the factory didn't torque them properly they may have loosened enough to allow a small squeak of compression to escape. I'd pull the plugs and inspect them, then reinstall them to the proper torque.

This may not be the issue, but at the very least you'll get to see how your plugs are burning.

-- Mark
They seem to be. I can't get a wrench on the top ones without pulling the tank though it looks like. I'll try harder on it next week when I can.
 

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Discussion Starter #7
Today it wasn't nearly as loud... Hit my 600 mile mark so it's going in Monday anyhow but... I did notice that in 3rd right around 20mph or (I think it was... will verify later tonight after a break.. it's 102 outside in the sun...) so just puttering along, right when you have throttle at the grab point to hold you at speed, you just give it a hair more and you can easily hear it. Still not as loud as yesterday... Give it a little more and start accellerating and it goes away. Back off and you go through that zone of loudness again back to mild at idle speeds. Without giving the throttle enough 'off' to actually take the load off the gearing, you can feather the throttle in this cruse space between holding, just backing off and just going faster, and control the sound...

Maybe it's just the lifters and intake vacuum things I keep hearing the guys talk about but I've ridden other 750's this year and none of them make this particular noise. It's very high pitched. Makes my ears hurt, even with protection. Perhaps the first service will remedy that problem. We'll see..
 

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Discussion Starter #8
Well, after the first 600 mile job, they found all three...

1) licenplate bracket. I found it initially and it wore off the paint on the fender. I fixed that one but then it slipped my mind for this one. Much better now that it's foam-isolated.

2) Valves and exhaust leak. The e4xhaust bolts were 3.25 turns lose to 18.5 ft.lbs. Valves were in dire need of a tweak.

3) Much smoother since fluids changed.

There is still some of the #2 there but that is the intake whistle which I knew should be there. But the metal ping is gone.

Much happier now...
 
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