This chirping noise just started out of the blue...no warning. I'm wondering if it could be the bearing in the fan blade that is worn out causing the blade to rub against either the radiator or the fan shroud. Any ideas?
What about the speedo cable? At low speeds I could hear a noise coming from the front of the bike. The speedo needle "wabbled" at lower speeds too. While I had the instrument cluster apart for another project, I took the speedo cable loose and dripped lubrication into the cable. When I got it back together and went for a ride, the wabble and the bird-like noise were gone.
If you think its the fan bearing , stick something in and try to move the fan up and down .???
The hardest thing about wierd noises is locating them .
When does the noise start ?
Where is it coming from ?
Can you make the noise start when the bike is stationary ?
Check the simple things first like rubbing plastic or rubber parts etc.
The fans do not run all the time so if it only happens when the fans run that could be it.
It has no speedometer cable so that is definately not it.
If it does it only when moving it could be brakes or a tire rubbing something. If it does it at a stop it could be the alternator.
The 1800 has a speedometer "cable", while the old LTD got stuck with a wire? I guess they went back to something that works. If it were an LTD, I'd have a good idea where to look, as mine was making a very similar noise, but the 1800 doesn't have those parts. However, it may have something similar. Mine was coming from a reed valve (2 of them actually) with rotted and leaking hoses on them. It made a chirp chirp chirp sound, very steady, while running. It had a rubbery sound to it, and was chirping because the reed valve was opening and closing, creating an intermittent vacuum leak. Is there anyway to disable the ignition, and see if it will make the noise while just being cranked by the starter? Mine did, and very loudly.
Mine was making a similar sound when coming home from Ohio yesterday. It's probably a different issue though. It seemed to only happen when I was accelerating or using engine braking. If I stayed at a constant speed it went away, if I pulled in the clutch and let the engine idle while going down the road it went away. It sounded like a cricket chirping very fast. It could have been because I was riding 2 up, but I can't say for sure because I didn't ride it to work today. I'm thinking that it might be something on the front of the engine or something, but I haven't looked into it yet. If I find out what it is I'll put the info here for something to check. I might even start another topic if I can't figure it out on my own.
Well, update on mine, I guess it was just that I was going through the mountains riding 2 up because when I rode today i couldn't hear the chirp at all. Sorry this didn't help your problem. I know that on my 86 Toyota pickup it chirped quite a bit until i changed out the PCV valve on the top of the engine. That probably won't help much either though. I would get a mechanics stethoscope or wooden rod and see if I could find the general location of the chirp (front/back/right/left, etc.). Just put one end of the rod on a location on the engine and put your ear up to the other. Then move around until the noise gets louder. You can narrow it down from there.