Ticking noise while driving.

So the last two days I've noticed a ticking noise that has started happening as I drive my bike around. It's not super loud, but it's loud enough to be noticeable while driving. When I hear it, I'll lean down towards the right side of the bike, and the left side of the bike trying to see if I can hear it more dominantly on one side. (I'm assuming it's something under my valve cover) But I can't really hear it on either side. The place I hear it the most is if I put my head down towards the center/front of my fuel tank by my handlebars and the sound comes loud and clear through there.

The other strange thing is that it only happens normally between 2000 and 3000 RPM either while accelerating or just cruising between those RPM levels. Anything above 3000 RPM and the ticking goes away. And after the bike has warmed up for a while, it will start to make the sound even when I'm stopped and idling. It's not as loud at idle as it is between 2000-3000 RPM, but it's still there.

As I said, I'm guessing it's something under my valve cover (lifters, valves, something....) But It just doesn't make sense to me why the sound goes away above 3000 RPM. Anybody have any ideas or input on what they think it may be?

 

I'd check the plug and coil wires, you may be arcing.

 

Check those valve clearences.

 

maybe it's the tach?

 

Do a Manual Cam Chain Tensioner Re-set.

Even though you have an Automatic Tensioner, ... sometimes they need a bit of encouragement if they're stuck (for whatever reason).

You do the Manual Engine turning.
Have an assistant "Drum-tap ... lightly" on the end of the Tensioner when you Turn-over the Engine backwards.

 

Thanks for the replies guys. I've checked the tack as well as the coils, spark plug wires, etc. Nothing there causing the ticking. I'm leaning towards valves or something still. But I did find something strange. I took it for a little ride to the point where it was warmed up enough for the ticking to be noticeable while at idle, then I took the seat and side farings off and then moved the tank backwards and sideways (but leaving the gas and vacuum line connected) to check everything underneath it while it was running.

Here is the interesting part. I then noticed that nothing specifically under the tank was making the ticking noise. Not even really any noise coming from the valve cover. (Beside what's normal) What I noticed next was that the ticking noise was coming from inside the gas tank. I put my ear up to the tank itself and it was loud and clear. I even lifted the tank off the frame and put it against my ear (still with the bike running) and the noise was still there sounding like it was something inside the tank.

Now... The strange part is that if I disconnected the vacuum and gas line from the tank, (still left the engine running with what fuel was in the fuel line) the sound disappeared from the tank, even if the tank was resting sideways on the frame as it had this whole testing period. Then, once I connected the fuel and vacuum line to the tank again, the ticking sound came back.

Is it possible that an internal engine sound could work it's way backwards through the carburetor, through the fuel line and into the tank thus amplifying the sound inside the tank? All while not making any additional sounds noticeable from just the outside of the engine itself? I wouldn't see this as even being possible considering all that is in a carburetor. Especially the jets. And even if it were possible, I would think the sound would come out of the air intake and be more noticeable there if it were even able to happen. So I guess I'm just kinda confused now. Maybe there is something inside the tank that is ticking inside it as the fuel is sucked through the petcock. And the speed of the flow changes it? Or maybe the old fuel level sensor that used to run to the Atari that I removed has a loose component ticking in there or something. I'm just randomly thinking here. If any of this brings any further ideas to your minds the input would be great. Thanks for your thoughts so far. (and sorry for such a long explanation... ha ha)

 

maybe the ticking is the petcock opening and closing in sync with the vacuum "pulse" from the engine?

 

terceseht
You must have really good ears- - try this once, run on "PRI" with the fuel hooked up, then while running, connect, and disconnect the vac hose.

 

Or your petcock has an issue and it's "blowing bubbles" into the fuel system and you can hear it.

Your petcock may have an internal vacuum leak, or its little "anti backup valve" is stuck. Or its o-ring is gone and it's beating itself to death internally.

Sounds like you tracked it to the petcock. Better have a look.

 

Pull the speedo cable off and take it for a spin. I've had this happen and took me some time to find it. Appears pretty regular for the xj700's at least. I have the issue on my airhead. A good shot of lubricant 1 or two times usually quiets it down.

 

Sorry to necro an old thread, but my 550 is doing the exact same thing and it is driving me NUTS. The ticking is loud and it is definately coming from the tank, I ran fuel lines 4 feet from the tank to the bike and the ticking is the tank. I took my petcock apart, but it looks great. Not sure what to do???