Disconcerting whining noise from engine

[Guest]

Hello all. I have another question about my '81 GS850G (with 17K miles). When it's running, it makes a fairly pronounced "whining" noise that rises and falls with engine speed. It sounds a lot like a supercharger or gear drive on a car. Is this normal, and if not, any guesses about what it is?

There is also an intermittent "clacking" noise that comes from near the clutch. I'm going to open up the clutch cover this weekend to investigate, but anything specific I should be looking for?

Thanks again y'all,

Scott

[tom203]

Whining,clacking.... Hmm

have you checked your camchain tensioner? Do you understand how it works?

[Guest]

Whining,clacking.... Hmm

have you checked your camchain tensioner? Do you understand how it works?

The cam chain tensioner on this bike was leaking when I bought it, so I bought a brand new one - along with a new gasket for it - and had a guy who claimed to be a whiz install it (along with several other things that needed attention). I wasn't able to be with him when he did the work, so I can't vouch for whether he really knew what he was doing, but based on the evidence of this and other tasks (e.g. he failed to install the new gasket), I'd say he's not nearly the mechanic he thinks he is. So if it the cam chain tensioner isn't installed correctly, I wouldn't be surprised.

And no, I really don't understand how they work. I'm all ears.

[Gorminrider]

Whines like an Old English car in reverse ? it might be "zooks syndrome"...ie: the nut is broken off the bevel gear under the rubber cover of shaft at engine...

link to browse but you can search for "whine" or whatever too.

http://www.thegsresources.com/_forum/showthread.php?242169-Whine-Whine-Whine&p=2339320#post2339320

there's a pdf by zooks titled Bevel Gear Shaft Repair at Bass Cliff's site. Lower right on the page

http://members.dslextreme.com/users/bikecliff/

[tom203]

I'd check tensioner myself and know for sure.
The tensioner is so simple that folks often mess it up. Your mechanic might fall into this group. I think on the 850 it's easy to remove,check operation and replace correctly without messing with carbs.

have a look at this link. If you held a tensioner in your hand, you'd probably understand its simplicity in a few minutes. The plunger shaft needs to push out against the chain guide (and not creep back) to take up chain slack or unpleasant things will happen.

http://members.dslextreme.com/users/storagecliff/images/engine_odds-n-ends.html#A05

[tom203]

Read that link! Your tensioner basically looks like this pic. The plunger and long spring on right side pushes out against camchain rear guide. It's driven out and held there by that knurled knob/spring gizmo at top. On bottom in pic, there is a lock screw and lock nut to aid in correct reseting and reinstalling should tensioner need servicing. The lock screw must be released (slightly) after reinstalling tensioner in engine or tensioner plunger won't do its job of pushing out!


image.jpg

[Guest]

Well folks, after a fair amount of studying its operation, I removed the cam chain tensioner today and sure enough, it had been improperly installed by my "mechanic". The set screw was still tightened up against the plunger, the lock nut was loose, and the big knob on the right was tightened all the way clockwise. So I loosened the set screw 1/2 turn to unlock the plunger, and with pressure from my finger on the end of the plunger, I turned the big knob as far as it would go counter-clockwise, allowing the plunger to recede into the body of the tensioner all the way. I then tightened the set screw to lock the plunger and reinstalled the tensioner (after a little more cleaning and detailing of the back of the engine). After I got it reinstalled, I loosened the set screw 1/2 turn again, and sure enough, I heard the plunger "pop" into place like it's supposed to. I left the set screw where it was and tightened the lock nut to keep it there. And what d'ya know - no more whining noise! Woo hoo!

Several attempts have been made to describe the operation of the tensioner, so here's my version:

The purpose of the set screw is to freeze the plunger in place; it keeps it from sliding either in or out. When you tighten the set screw, it freezes the plunger wherever it is. When you loosen it 3/4 of a turn or less, it allows the plunger to move within a limited range. But if you loosen it more than 3/4 of a turn, it will allow the plunger to come completely out of the tensioner. Sometimes that's good, sometimes that's bad - depending on what you're doing.

The purpose of the big knob on the right is to control how far the plunger recedes into the body of the tensioner when you apply pressure to the end of it. So two things are happening at once: with pressure on the plunger, it will recede into the the body of the tensioner as you turn the big knob counter-clockwise. The big knob will only go so far; when it has reached its maximum, the plunger will be fully recessed into the tensioner. When you reach that point, let go of the big knob and tighten the set screw on the plunger. The big knob is always spring loaded to want to turn itself clockwise, so when you turn it counter-clockwise, you're turning against that spring tension.

I took before and after videos (with sound, of course), and if I can figure out why they won't upload to Youtube, I'll add a link to them on this thread.

So one more step towards making her "right"! I hope all this is helpful to someone. And you "Gurus", if I did anything wrong, don't be afraid to speak up!

[Guest]

Ok guys. I figured out this morning why I couldn't upload any videos to Youtube: my version of Firefox wasn't the latest and greatest. I had Version 47.0.1; it wanted Version 47.0.2. Geez..... picky! So I updated Firefox and it worked perfectly.

Anyway, here is a link to the video taken "before" the operation....

https://www.youtube.com/watch?v=WHHLhNEWk5I

And here is a link to the video taken after the operation....

https://www.youtube.com/watch?v=xC3qeODq-SU

[bonanzadave]

Nice looking 850. And it sounds good too !

[850 Combat]

When the whining stops, she has fallen asleep or fallen off.

[AMK]

Nice bike!
What's the difference between a puppy at the back door and a woman at the back door?
The puppy quits whining when you let it in.

[Guest]

Nice looking 850. And it sounds good too !

Thanks. You ain't seen nothin' yet. I'm slowly but surely putting her back like she started out. There's a lot of touch-up to do on the frame (lots of chips from stones and such). I also have a much closer-to-new seat to put on, complete with the chrome strips (and blue tape inserts), and the correct passenger grab bar - when the mechanics are sorted. This weekend I fixed the noisy cam chain tensioner and tightened the big 32mm nut on the clutch basket. Next weekend is the valves. Then the carbs. I'm detailing stuff as I go, so it's gonna be nice by summer.

Watch this space....

[tom203]

Now that you have discovered that you are the best mechanic for your bike, when you remove the cam cover to do those valve checks, have a look (if possible) at rear chain guide in case it was tortured by the tensioner error. Might as well check camshaft to crankshaft timing to know it's perfect.

[Guest]

Now that you have discovered that you are the best mechanic for your bike, when you remove the cam cover to do those valve checks, have a look (if possible) at rear chain guide in case it was tortured by the tensioner error. Might as well check camshaft to crankshaft timing to know it's perfect.

Hi Tom. Yes, I think I have discovered that I am the best mechanic for my bike - at least until it comes time to go into the engine. But I don't expect to ever have to do that; the bike only has 17K miles on it and seems pretty tight (in a good way). I don't ride much, and when I do, I ride pretty conservatively.

Those two suggestions both sound like good ideas. I'll look as much as I can without disassembling anything any further than is required for doing the valves. Also.... if the camshaft-to-crankshaft timing were off (even a little bit), wouldn't it be really noticeable? The bike runs pretty well right now - except for the carb issues.

[Blue Falcon]

did tightening the nut get rid of the rattle?