83 VF750f - Whine at higher speeds

Hi all, I'm after a bit of expert advice again, after all the useful info I received last time.

I've noticed quite a loud whine from my VF750 when I go above about 40mph.
It doesn't seem to be coming from the engine, more from the front of the bike, near the intake, or around that area.

The noise only appears once I've speeded up, no matter which gear I'm in, and it sounds like a bit like a hairdryer... nothing grindy about it... no loss of power or anything like that... It almost sounds like the wind whistling through the fairing or something

But when I slow down again the whine doesn't go away instantly. I can even be stopped at lights for a few seconds sometimes before it disappears again, and it won't re-appear until i get back up to higher speeds again. (so I'm thinking it's just some kind of dodgy cooling / intake fan?, but I can't see anything obvious)

It doesn't seem to get any louder or quieter regardless of how fast I actually get up to, but it gets a bit harder to hear when the engine gets louder anyway, so I can't be totally sure of that.

Any suggestions?

 

If it went away when stopped, I would suspect the speedo cable/gearbox. How soon after you've stopped does it go away? Does it happen mostly when it's cold outside?

 

Radiator fan? The air flowing through the radiator can make the blades rotate. If they get going fast enough they will keep spinning for a bit once you slow down. I can't say that I've ever seen this before personally, so it's just a theory. I'm sure it is annoying but probably not anything to be too awfully concerned about. It might be worth observing in case it gets any worse.

 

This is the type of thing it sounds like.
I'm not overly concerned about it, just sounds 'obviously wrong'.

It does sound like something winding up and then winding down, rather than a permanent noise.

If it was something as serious as the gearbox I'd assume the noise would be there most of the time. But the bike can be ridden in 5th gear at 30mph with no problem, and the noise occurs no matter which gear I'm in.

I doubt it will go away on it's own, but it's not a show-stopper so I'm not going to worry about it too much.
I just wondered if anyone had experienced anything similar.

 

I think I have the same issue! I'm pretty sure it's not the rad fans though, as I have mine hard wired to a switch, and usually they're on. When the noise come about, the fans are not moving when off, and when the fans are on it makes no change to the noise.

 

I'd re-read post #2, then get busy lubing your speedo cable...............

If you can get the front end off the ground and spin the wheel, you'd likely be able to hear the noise.

 

Yeah that's what I will try tonight! I think I will jack up the front wheel and take the power drill with a buffing attachment on it sans pad (just the rubber disc) and see what I can get!

Thanks again squirrel!