What options for identifying a loud tic in left cylinder

[malmac]

R75 left cyl 1.mp3

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Here is the sound file for the left cylinder.

Mal

[schrader7032]

Definitely something. It will be helpful if you can prod around and find the spot where the sound is the loudest.

[malmac]

Kurt

The electrical system is shut down, so I have to get that fixed first befrore I can continue with the noises.

Thanks for you help and interest.


Mal

[cbclemmens]

My 75 year old ears that spent most of those years too close to running equipment can't help you much.

Craig

[malmac]

Hi Craig

Well I am glad you are still with us and enjoying your motorcycle/s.

The electrical problems seem to be working themselves out, so I might get back on to this thread soon.


Regards Mal

[srankin]

Mal, I am sorry, I don't have the hearing to determine from your recording. One ear is gone, the other going.

Refresh my memory as to how many miles are on the bike?

Have you considered doing a leak down test, do you have the gear to do so? It looks like you have everything adjusted as should be, a leak down test will give you an idea as to the shape of the valves as they fit into the seats and stuff. St.

[malmac]

Hi St

Yes I have the gear to do a leak down test.
The bike has 100,000km on the clock and it seems probable that it might be close to right.
I suspect from the sparkplugs that a new set of rings and maybe a rebore is going to happen in due course.
At the moment "Cucumber" is behaving like a "Gherkin" so we are in mechanical therapy.

As I settle down each major function, then I will retrace my steps and pull off the heads and tidy up any deficiencies ) such as valves, pistons, and so forth).

I will keep you posted on progress.

Regards


Mal

[malmac]

Well I checked the adjustment on the valves at TDC. All good. .20 Ex and .15 In.
Ran the bike and the TIC was still there.

I then popped the covers off and ran the engine to check oil flow..... excellent.

When I stopped the engine I felt the left ex clearance and it was excessive. Measured at .25
End float is fine.
Then I noticed that the engine had not stopped at TDC and the inlet valve was still open.
I marked the flywheel with a sharpie.

Turned the engine to TDC.
Checked the clearances.
.20 Ex and .15 In.

I then re checked at the point where I had marked with the sharpie.
.25Ex Inlet valve open.

So my next step will be to remove the valve gear and inspect the rocker shaft, needle rollers and rocker arm for excessive wear points.

Any other thoughts are most welcome.


Mal

[therealkennyboy]

A bent/bowed push rod can cause an audible tic. Maybe back off the rocker arm adjustments (let the pushrod free float) and spin one with your fingertips to check for out-of-round or a rough spot? If you go all the way to pulling them out, roll them on a glass plate or other known flat surface.

Good luck chasing it down.

[malmac]

A bent/bowed push rod can cause an audible tic. Maybe back off the rocker arm adjustments (let the pushrod free float) and spin one with your fingertips to check for out-of-round or a rough spot? If you go all the way to pulling them out, roll them on a glass plate or other known flat surface.

Good luck chasing it down.

Thank you for the tip.

I have ordered a new shaft and needle rollers and a new pushrod.

I am hoping the problem wont be at the camshaft end. I have enough other engines pulled apart to be repaired. Dont need another major engine job.


Mal