Engine knocking need help identifing

[dan filipi]

Anything new on this?

 

[Jalvarez]

I posted 2 additional videos for your review. Any help would bwe appreciated

https://youtu.be/5bUh7QEHBck

 

[dan filipi]

Sounds like it runs great otherwise.

Hmm is right.

The first time you pulled #2 wire it stopped, second time it didn't.

Is the noise as loud in real life as it is in the video?

To me that's too loud to be a valve bumping a piston and by now the valve head would be bent and not hitting anyway.

By the pitch I can't see how it's piston related. Gotta be top end.

This is a tough one.

 

[dan filipi]

Sometimes it's easier to get ideas without video so I pulled just the audio track out.

[flv]https://classicgoldwings.com/forum/vids/JalvarezGL1100Knock.flv[/flv]

 

[Heath]

I was actually looking for sparks. Could it be a short in one of the plug wires? Try running it in the dark and see if it's an electrical issue.

 

[dan filipi]

No, spark leak is a light tick which can be heard when he pulled the plug wire.

Thoughts.
It seems to be at piston speed, plug length too long bumping the piston?

So far I think we can rule out the oil and water pump.

I'll keep thinkin on this.

 

[slabghost]

It is very loud but could be grounding spark. Try running it in the dark and look for stray spark. It may not be mechanical it sounds intermittent to me. Missing a few cycles once in a while. Too tinny a sound to be pistons , rods , or mains. You may be right about a loose bolt hitting though. I'll think on that one before I can suggest where it might be.

 

[Jalvarez]

Dan, Mcgovern & Scdmarx:

Hello again I posted another 2 videos to see if you casn help identify the tapping noise.

Regards

https://youtu.be/5bUh7QEHBck

 

[dan filipi]

Well maybe spark jump but it sure sounds too loud to me.

I had spark jumping from the boot when plugged in, it sounded similar but again, not that loud unless the camera is amplifying it so much more over the engine noise.

 

[mcgovern61]

My observation...when the #2 plug wire is pulled the first time you can hear the spark jumping to the head. That spark jump is at exactly the same speed as the tapping sound. So it is at piston speed. Is it possible that the spark is jumping to the piston?

What plugs are these?

Then the second time it doesn't stop the tapping. When the speed is slowed to 950 RPM, it becomes intermittant. Hmmmm.............. I am going to have to take a look at my '81 engine.

 

[AApple]

My first thought was spark jumping, but...like Dan says, it really sounds too loud for that. Could it be a problem with the cam?

 

[mcgovern61]

My first thought was spark jumping, but...like Dan says, it really sounds too loud for that. Could it be a problem with the cam?

I'm going to tap around my camshafts to see if the same sound can be found.

 

[mcgovern61]

Checked a set of heads off the bike and the cam doesn't have that frequency. When the rockers are bathed in oil, they get a dull sound. The sound of the valve lash is still not quite the same as your noise. I tapped around and the head itself resonates with the same frequency. Looking at the heads that are off, there is little chance of valves touching without damage. However, is it possible that you are 1 tooth off on the cam pulleys?

 

[joedrum]

i cant listen to it has anyone thought it might be the stator bolt loose

 

[Jalvarez]

Tried running it in the dark to see if it's an spark issue and it does not seem to be the case.

Again can starter chain be hitting something?

It still sounds like the valve is hitting or a bolt is hitting on something.

1 tooth off on the cam pulleys is not the case. Second video shows the timing alignment to be spot on. Should I try moving the cam 1 tooth up or down?
will that not cause the valve to hit the piston?

the noise seems to be too far from the stator for it to be a loose stator bolt-(Not sure on this)

The sound comes clearest from the #2 cylinder (seems louder on the exhuast valve).

Tomorrow I will for the s3econd time change the rockers from another head to see if anything changes.

 

[Jalvarez]

Jorg: asked
Is the noise the same hot or cold? Can you hear it just cranking it with the ignition off?
Noise same hot or cold. I tried the starter with no plugs and the sould is not presernt unless i have ignition.

Dan: Oil pump?
I checked the water pump and it was clear with no play?
do you think it could be the oil pump? I don't understand why is the sound is loudest close to the #2 piston exhuast valve.

 

[mcgovern61]

do you think it could be the oil pump? I don't understand why is the sound is loudest close to the #2 piston exhuast valve.

Hmmmm.....this might be dumb, put pull the clutch, drop it into 1st and ease the clutch out just enough to put pressure on the plates and try popping the gear shift up to neutral all the while listening if the tapping changes.

 

[Jalvarez]

Gerry: Did as you asked no change in the noise ran though all gears noise still present

 

[mcgovern61]

Worth a try.....just making sure it is not gearshift related....shifter is right under the head. I have watched the video several times and you can see that the tap is not the same speed as the intake valves (at the rockers). Of course the exhaust rockers are bathed in oil so it is harder to watch them. I can duplicate the sound when I tap my heads with a steel socket wrench, but not any other tool leading me to think it is a steel against aluminum sound.

Slower speed and pulled plug wire changes it a touch which seems to indicate a change in load on something....but what?

 

[esker]

Jalvarez
That tapping noise sure sounds like it could be spark related. It reminds me of having heard the same sound on one cylinder on my 69 BSA. I had a fouled plug and when I pulled the spark plug wire off the spark plug, it made a similar sound as what I hear in your video and the spark plug would fire. I think the spark was jumping from the terminal of the plug wire to the spark plug cap inside of the rubber boot of the spark plug wire. I could not see a spark but I certainly could hear it. Watching the last video I can see the spark jumping from outside the plug wire to the engine and at that same moment your tapping noise dissappears. It also seems to be intermittent as you say that the noise will dissappear from time to time, especially when the idle speed is very low.
What is the condition of your spark plugs, wires and coil? Plugs are quick and easy to swap around.
Stay the course and continue to look for the souce of the tapping noise at #2 cylinder. Do you have one of those mechanics stethoscopes that you can use to pinpoint the exact location of the noise?