Loud clanking noise in engine - 1982 GS650 GL

[Freebeer]

Hi guys,

I have an issue with my engine on my 1982 GS650 GL that I wanted to run by you before I started tearing everything down.

I was riding on the interstate, going about 70mph, and I started to lose power slowly. I noticed the engine was making a clicking noise (very loudly, but it was hard to hear with no windshield and going 70). Eventually, I lost almost all acceleration power and was only going around 20mph and the engine died.

I have the bike home now, and the bike will start and idle, but there is a loud clacking noise coming from somewhere on the engine.

I have taken the valve cover off, and everything looks fine in there. I have done the valve shims previously.

Here is a video I posted to Youtube of the engine idling. https://www.youtube.com/watch?v=7lQl...ature=youtu.be

Thanks in advance.

~Freebeer

[tom203]

Start by removing valve cover again: does cam chain have too much slop? Did you/have you checked tensioner to make sure it's working as intended? While you in there, check crank to camshaft timing- remove signal generator cover and inspect.

[Freebeer]

Start by removing valve cover again: does cam chain have too much slop? Did you/have you checked tensioner to make sure it's working as intended? While you in there, check crank to camshaft timing- remove signal generator cover and inspect.

Hi Tom,

Thanks for the reply.

I will be tearing it back apart to check on everything as you said.

I didn't mention that after the incident on the Interstate, I did take the valve cover off, and removed the chain tensioner. I had suspected that the tensioner wasn't working properly, as that was basically the only part I hadn't touched yet on the engine (besides internal stuff). I cleaned the tensioner, and everything appeared to be working correctly. I re-installed it (using the proper procedure), and it looked like it tensioned the chain. I also checked timing with the two shafts, and made sure the chain had the correct number of links between the two sprockets (21 if I remember correctly).

All that being said, I am going to take it all back apart and re-check everything to make sure I didn't miss something.

Thanks, and I'll keep you posted.

~Freebeer

[tom203]

Yes, best to start with valve stuff, even though your loss of power seems odd to me.
just to make sure regarding tensioner....
You wound its knob back ,pushed plunger in, tightened down setscrew on plunger shaft(to hold it in position),installed it in engine and then released setscrew 1/3 turn (to let plunger push out). Then tightened lock nut to prevent setscrew from interfering.
You seen this pic?

image.jpg

[Freebeer]

Thanks for the picture. I hadn't seen that one before.

As for installing the tensioner, I did the correct procedure. I was paranoid after reading so many posts on gsresources, so I made sure it was correct. It was very satisfying seeing the chain tighten up as the tensioner pushed its way in.

I am also planning on shining a flashlight down each spark plug hole to see if there is any visible damage on top of one of the pistons.

[earlfor]

Yes, best to start with valve stuff, even though your loss of power seems odd to me.
just to make sure regarding tensioner....
You wound its knob back ,pushed plunger in, tightened down setscrew on plunger shaft(to hold it in position),installed it in engine and then released setscrew 1/3 turn (to let plunger push out). Then tightened lock nut to prevent setscrew from interfering.

Why would anyone wind the knurled knob on the cam chain tensioner? Winding or unwinding the knob does not change the tension that the plunger will apply. That knob is not meant to be "wound".

[londonboards]

That sounds like a valve or tappet. Maybe a split shim? It's very distinctive not at all like a chain slapping around. Are all the cylinders heating up?

Greetings

[tom203]

Why would anyone wind the knurled knob on the cam chain tensioner? Winding or unwinding the knob does not change the tension that the plunger will apply. That knob is not meant to be "wound".

Last time that I checked you can't push plunger back unless you wind/turn knurled knob back. The knob has its own spring which pushes on ball that pushes on plunger ramp-it's a no go backwards unless knob tension is released.

[earlfor]

Last time that I checked you can't push plunger back unless you wind/turn knurled knob back. The knob has its own spring which pushes on ball that pushes on plunger ramp-it's a no go backwards unless knob tension is released.

Ahhh, I didn't realize that was what you meant. I read it as turning the knurled knob directly retracts the plunger or puts tension on the plunger spring. heh eh.