High-pitch Squealing Sound from Front

[natejelovich]

Hi All,

Not sure if this is the correct place for this question, but figure it's a "tuning" question.

Anyway, when riding my '79 850, there is often a high-pitch squealing sound coming from the front end. I don't know where exactly (that's kind of my question) but it sounds like the front "dashboard" (if you call it that on a bike...).

My question is, is this common? And if not, any idea why, what, and where from this noise could be coming from?

It's really only when I'm riding (not idling) and get's louder the faster I go... but then will sometimes stop for a few seconds and then start back up again.

Not sure if something is loose, a cable is bad, or there is some other problem...

Any thoughts or where I might start in order to better diagnose the "problem" (if there is one) would be super appreciated!

Thanks all!


Nate

[chuck hahn]

Sounds like maybe the tach or speedo cable is routed wrong and the core is rubbing hard against the inner sleeve?? Does it do it sitting still and does it get more with added RPMS???

[kdo58]

disconnect one cable at a time, ride see what happens.

[natejelovich]

No, doesn't do it when sitting still and yes, louder with added RPMS (but then will go quite sometimes).

I thought it was a cable issue too... could it be rubbing?

When I first bought the bike, the needle in my speedometer was jumping all over the place, so I used some graphite lubricant to grease it up (took out cable from sleeve and rubbed graphite on it).

I don't know if it's connected or not, but figured I'd mention it.

How would it be routed wrong? Or maybe the question is, how should they be routed?

[chuck hahn]

It comes up from the backside of the tree and up to the speedo nut screw on point. Things is it just shouldnt be sharply bent when routed and it shouldnt pinch or kink when you turn the bars. I would take a red straw and bend it so you can squirt some lube up into the gear drive on the bottom of the speedo too. Also when your moving take your hand and touch diffeent things..head light, speedo and cable tach etc etc to see if it stops when you hit the right thing.

[DanTheMan]

Dragging brakes will squeal. If you've had your front wheel off and didn't get it centered properly, that will cause a squeal, as will dry wheel bearings, or a dry speedometer drive on the front wheel.

[Guest]

Dragging brakes will squeal. If you've had your front wheel off and didn't get it centered properly, that will cause a squeal, as will dry wheel bearings, or a dry speedometer drive on the front wheel.

My guess is the front brakes, does the noise change with the speed of the motorcycle?

[natejelovich]

My guess is the front brakes, does the noise change with the speed of the motorcycle?

Yes, but not always. It sometimes get's higher and faster (quicker whine) when speeding up.

[tkent02]

Lubricate the speedometer itself, not just the cable. And the tachometer.

[Guest]

Yes, but not always. It sometimes get's higher and faster (quicker whine) when speeding up.

What happens when you slow down?

Does it vary with the engine rpm?
There's got to be a way to pin it down.
Does it change at all when you squeeze the front brake lever.
Tire chaffing on the fender?

[natejelovich]

What happens when you slow down?

Whine decreases in pitch and "speed"

Does it vary with the engine rpm?

Yes

Does it change at all when you squeeze the front brake lever.

I'm trying to remember right now, but no I don't think so.

Tire chaffing on the fender?

Nah, tire seems totally clear/fine...

Tons of great things here from everyone. Thank you!! I love this forum.

I think I am going to try and grease up the tach and speedo cables.

Question, how do I grease/lubricate the actual speedometer? Spray inside the speedometer itself? I think that's what's been recommended, but want to make sure... Seems like a lot of electrical parts could get damaged.

[tkent02]

Nothing electrical in there. Grease in between the inner part that the cable turns, and the outer part that it turns in. Easiest if you turn it all upside down first.

[natejelovich]

Nothing electrical in there. Grease in between the inner part that the cable turns, and the outer part that it turns in. Easiest if you turn it all upside down first.

Ah ok, I think I got it. Just the places where the cables connect. Not inside the actual speedometer itself.

[tkent02]

That's what squeals is the inner spinning part inside the outer part. There is no bearing, just the one part spinning inside the other. Grease will make it turn smoothly.

Tach and speedometer are the same.

[chuck hahn]

Little red straw in the nozzle and turn it up toward the fittings. Thats spray white lithium grease is very good for the job and will last a long time in there.