[Jan]

Hi!
I have a 2016 RE Classic 500 with almost 28000 kilometers on it. Now a strange noise is heard from the engine.
It is not possible to determine more precisely where it is coming from.

It sounds much like an old alarm clock that rattles about once per second.

I started by changing the oil and oil filter but it made no difference

A mechanic helped me replace the parts listed below and the sound disappeared!
But - after a few kilometers of driving it came back - first very quietly and then with the same force as before

I am attaching a short video where I hope you can hear the sound in addition to the usual clicking sounds.

If any of you can help me understand what is wrong, I would be very glad!

(I live in Sweden but only drive in temperatures down to + 10 degrees Celsius)

Regards
/Jan

GASKET, ENGINE COVER (RH side)
GASKET, OIL PUMP OUTLET (571115)
O RING, OIL PUMP OUTLET (570293)
TORSION SPRING (570108)
FLY WEIGHT (570541)
PIVOT (570105)
PIN ASSEMBLY (570110)


[attachment deleted by admin]

[johno]

Id does sound like the auto decompressor or an air locked hydraulic tappet, does the noise go away at slightly higher revs?

[Jan]

Hi and thank you for responding to this!
The sound is there al the time - also by higher revs but the frequency has no clear connection to the revolutions - It`s about the same i think.

[om15]

My decompressor made a clacking noise but a previous owner had used 10W40 oil, with the correct 15W50 semi synthetic oil it fixed it.

[axman88]

Just to be clear, are we talking about the regular "tic, tic, tic" sound, that seems to correspond to the firing events, or the clave-like "Tock" sound that occurs every 6 or so "tics", and just twice in the recording?

[Jan]

I have always used the 15W50 oil.
I got the advice from the mechanic to try a 40 oil and see if it makes anny differens but I have not tryed this yet.

It is the clave-like "tock" that just occurs twice in the recording which I am concerned about but the tic-tic-tic is quite strong.

[SteveThackery]

That loud tick is definitely at valve gear speed.  It is severe enough to suggest a real fault - I would urge you not to ride the bike like this.

As for the "tock", I can't hear it clearly enough to guess what it is. I agree, though, that it needs investigating. But I repeat: that ticking is severe and something is definitely wrong.

About the loud tick - there are several possible causes, some of which have already been suggested, but really all we can do is make guesses.

I recommend taking the side cover off, and the valve covers on the cylinder head. You are looking for excessive valve clearance, or play or looseness in the moving parts. Check the rocker arms for wear, and confirm that they are tightened down to the head.  Observe the action of the lifters as you rotate the engine.

It looks like all the decompressor parts have been changed, so it could well be a collapsed hydraulic lifter. Unfortunately, you're going to have to get in there and inspect.

[SteveThackery]

I have always used the 15W50 oil.
I got the advice from the mechanic to try a 40 oil and see if it makes anny differens but I have not tryed this yet.

Nooo! The only oil you should use it what it says in the handbook. Putting syrupy 40-grade in there, hoping to quieten the noise, is a massive bodge and the mechanic should be ashamed of himself for suggesting it.

[axman88]

The OP's machine "tic, tic, tic" doesn't sound all that loud compared to my C5.  But, I suspect mine has a lazy lifter, and it's hard to compare sound in a recording vs. real life.  Was thinking of pulling them out and cleaning them.  But, I would try an oil change with a pre-flush using an engine cleaner first.

One thing for sure, when my decompressor cam broke and was stuck ON, that was quite a step up in sound intensity, and I'm not hearing anything like that in the recording.

One candidate for the origin of the "toc" sound might be an electric arc happening in the spark wiring.  My C5 started making an intermittent arc at the cable / spark plug cap interconnection, for just a short while, before it fried the internal 5k resistor.  Somebody at the factory decided 3 twists was adequate and the connection was quite loose at both ends of the spark cable.  That resulted in a 2.5 mile push home.

[Jan]

Thank you all for all the thoughts and advice.
Yes, we replaced the decompressor parts and the sound dissappeared for a few kilometers. It seems that we somehow affected the error but did not solve it.

[SteveThackery]

The OP's machine "tic, tic, tic" doesn't sound all that loud compared to my C5.  But, I suspect mine has a lazy lifter, and it's hard to compare sound in a recording vs. real life. 

What concerns me is that only one of the lifters is making that loud tick. The valve gear in my UCE was bloody noisy for saying it had hydraulic lifters, but the noise was from both valve trains equally.

I would not be comfortable riding the bike if it were mine. It needs fixing, in my opinion.

[Freddy1]

I have no idea what the origin of that strange noise is.

It is strange that the noise occurs every 12 revolutions of the crankshaft.
It is strange that after changing the decompressor the noise disappeared for a few kilometres, a malfunctioning decompressor would cause a noise every 2 revolutions of the crankshaft and not every 12 revolutions (however the torsion spring p.n. 570108 is obsolete, it has been updated with new p.n. 570108/F)

Out of curiosity, I would also test the noise with the clutch pulled and a gear engaged.

[Jan]

Interesting - I have not noticed that only one lifter is ticking - yes that is worrying.
I have thought that the tic tic tic sound is normal for these machines after all.
Maybe it´s been increasing slowly and i have`t noticed the differens

[Jan]

Yes, very strange symptoms - I will try with the clutch pulled and a gear engaged

[Monkee]

From what I've read and talked to people about the most common causes for ticking in the c5 are:

Cam backlash
Auto decompressor
worn pushrods
worn rockers/loose rockers
hydraulic lifters not lifting
 
those are the most common and not impossible to fix.

[Jan]

Thank you for this! perhaps there are several factors here that need to be investigated

[Silverback]

i would get a cheap mechanic stethoscope. it will help you to pin point location of sound.
my guess it decompressor and or lifters.


i was worried about that sound early on in my 2011 c5 ownership.  checked back lash , valves etc. everything was fine.  i have since embraced it and things are still running great.

I even thought maybe oil wasn't reaching valves. Left valve cover off and verified oil flow.
I think it decompressor.  When you check yours out you will see how it moves about freely.   I snugged  up the scree and iuckly realized it needed to move freely.

If you want to verify just take decompressor off. Hey are easy to take off and install. Crank the engine.   
https://www.harborfreight.com/mechanics-stethoscope-63691.html?utm_source=google&utm_medium=cpc&utm_campaign=12144811130&campaignid=12144811130&utm_content=117789287518&adsetid=117789287518&product=63691&store=&gad_source=1&gclid=CjwKCAiAt5euBhB9EiwAdkXWO5NXKNyGKXkP5y27kZTcWgRUVK1zo7_CUHYnbV4wvlOiXKEK2UYf0xoCszcQAvD_BwE

[Haggis]

Yes, very strange symptoms - I will try with the clutch pulled and a gear engaged

Have you checked the endfloat on the cams?
They should both have at least one thrust washer.
It's a very strange sound though, like an old grandfather clock in the background.

[Mad4Bullets]

I would suspect that the noise could be coming from excessive cam gear lash, which is adjustable. With the side cover in place I'd expect a similar deep occasional knocking sound. Here are three sequential videos on the subject that may be of interest. Good luck.

https://youtu.be/noANYelOdGY
https://youtu.be/LF2hCvyMQ7Y
https://youtu.be/OBFe4qa4Bp4

[SteveThackery]

With the side cover in place I'd expect a similar deep occasional knocking sound.

Why? I'm genuinely interested, but I can't get my head around why cam gear backlash would make an occasional knocking sound. Why only occasional?

On my Bullets, excessive backlash made an engine-speed rattle, very much like loose tappets. This is backed up by the second video where he demonstrates what the backlash sounds like.

[Haggis]

Yep, I agree that excessive backlash play would sound like noisy tappets rather than the deeper irregular noise in the video.

[Jan]

Hallo again - after some traveling I am back.
I have now tested to run the engine with gear engaged, standing still with the clutch engaged- the sound is still there and at the same interval.
 

[Monkee]

Hallo again - after some traveling I am back.
I have now tested to run the engine with gear engaged, standing still with the clutch engaged- the sound is still there and at the same interval.

Might be a dumb question but have you ruled out piston slapping?

[SteveThackery]

Might be a dumb question but have you ruled out piston slapping?

There are no dumb questions! Piston slap is something you hear as a continuous, rapid "clacking" at the same speed as the exhaust pulses. The OP's noise is an occasional, intermittent "thunk". I admit to having no idea at all what it could be. 

[axman88]

Hallo again - after some traveling I am back.
I have now tested to run the engine with gear engaged, standing still with the clutch engaged- the sound is still there and at the same interval.

A longer video, with more than the two "tock" events of the first, and wherein the vantage point circles the engine, and the microphone points at various noise makers on the engine, might be helpful for the forum to help you figure out what this might be.

And, $10 spent on the right tool might help you in narrowing down the source.  https://www.amazon.com/Stethoscope-Stainless-Mechanics-Cylinder-Diagnostic/dp/B08NQRR32K/ref=asc_df_B08NQRR32K/

[Freddy1]

 I also thought it could be the primary transmission chain with a damaged link but the frequency of the noise doesn't convince me.
However, just to be sure, I would check the primary transmission chain, in my Bullet I replaced it at 30,000 km because it was breaking, but it didn't make any noise.

[axman88]

I also thought it could be the primary transmission chain with a damaged link but the frequency of the noise doesn't convince me.
However, just to be sure, I would check the primary transmission chain, in my Bullet I replaced it at 30,000 km because it was breaking, but it didn't make any noise.

Referring back to the original video, which is ~2.9 seconds long.  I'm hearing:
  -21 "Tics" of the valve action, with the video ending just as the 21st "tic" sounds.  That means 42 revolutions occur which calculates to around 870 rpm.
  -The 2 hollow "tock" sounds occur just before "tic" #6 and just before "tic" #18.   That means the "tock" sound was spaced apart by ~24 revolutions.
  -The primary drive ratio on this engine is 26/56, which is 2.15.  The primary chain has 80 links, so links on the chain will be at the same cyclical position in travel every 3.077 revolutions.

It's not impossible that a defective link arranged itself to hit something internal then did it again, (harder) after 8 cycles, which would have been 3.077 x 8 = 24.6 crank revolutions, (12.3 "tics") later.  This seems consistent with what we hear. 

It's easier to perceive the audio if you slow down playback.  A longer recording might reveal more.   

A primary chain that is about to fail would be a very good thing to find BEFORE it lets go.  There is a known issue with the chain tensioner on this model being "too ambitious" and overtightening primary chains.   I took the spring out of mine, and made it a manual operation.

[Guaire]

There are many good suggestions here. The best one’s involve removing the right side engine cover. It seems like everything you need to see could be accessed from opening the right side.

[SteveThackery]

It's not impossible that a defective link arranged itself to hit something internal then did it again, (harder) after 8 cycles, which would have been 3.077 x 8 = 24.6 crank revolutions, (12.3 "tics") later.  This seems consistent with what we hear. 

It's not impossible, but to the smell test it seems extremely unlikely, especially as it isn't a nice integer value. This is my subjective judgement only: the next step is to get both covers off and have a poke around. Especially as there is something very wrong with one of the lifters. That tappet "tick" is way too loud.

[SteveThackery]

There are many good suggestions here. The best one’s involve removing the right side engine cover. It seems like everything you need to see could be accessed from opening the right side.

And the left side if you want to check out the primary drive.

[Jan]

Thank you all for these assessments! I will talk with the mechanic helping me to see how we can follow up on the advice.
Unfortunately the forum is blocked for larger files - I couldn`t add a longer video despite compression - I`ll see if I can arrange it.

[axman88]

Thank you all for these assessments! I will talk with the mechanic helping me to see how we can follow up on the advice.
Unfortunately the forum is blocked for larger files - I couldn`t add a longer video despite compression - I`ll see if I can arrange it.

One would find a video hosting site, put the video there, then share the link here.  This is actually good policy for all large files, including images, and makes it more likely that attached files will be available years in the future.

[SteveThackery]

One would find a video hosting site, put the video there, then share the link here.  This is actually good policy for all large files, including images, and makes it more likely that attached files will be available years in the future.

Yep - you can stick it on YouTube and make it private, so only visible to those you've shared the link with. I do that quite often.

[Blackdog62]

Is the correct decompression pin fitted there are two sizes 3.8mm and 4.0mm I have the exact same issue, I've found my bike has the 3.8mm decompression rod fitted but it's way too small and I've ordered the correct 4.0mm one jyst waiting for it to arrive, but for sanity sake make sure to use the correct grade oil and get the mechanic to try and lift the rocker arms with a screw driver yo see if the hydraulic lifer has failed is should be very hard and you should be able to more the valve first if all checks out the I'm afraid it the right hand cover off again I see the mechanic has already been messing with the decompression system this will have yo be checked again yo make sure the correct pin is fitted also check the cam backlash at the same time just to be sure then make sure the pump o ring is in place and re assemble (please note the rocker covers and vanle train will need removing to adjust and check the backlash it's worth checking fir and signs or wear on the valve rockers