Very annoying clicking/ticking/buzzing electrical sound

[hugomez]

Hi guys,

I have a problem on my "other" bike. I hope nobody get offended if I ask here for technical support for a non Rumi motorbike, but in my usual Honda forum where I ask for technical help I can get solution.

The problem is a very annoying clicking/ticking/buzzing sound coming from my spark plug area.

This sound is not there all the time, but every time I use the bike it appear sooner or later. It came and go, not remain there once it appeared.

I tested many times replacing part by part with no result. I replaced the spark plug, the spark plug cap, the ignition points (and adjusted it properly), and also I replaced the condenser.

The bike run well, but this noise is driving me crazy, sometimes this electrical clicking is very strong.

When the sound started appearing some time ago I was thinking that was coming from the spark plug area, later I was the filling that was coming from the ignition points, but later again I think is coming form the spark plug cap area.

I ordered a cheap (copy) coil on ebay and I'll replace once it arrive, but if I carry on this way I'm going to replace all the electronic system with no success getting rid of this sound.

If any of you know about what can be the source of the problem for this electric buzz/clicking/ticking noise please give me a clue to test on my bike.

The bike is a Honda CB100 from 1970, engine is a 4 stroke, single cylinder, 100cc motorbike, 6V system.

Thanks in advance and I promise that I will keep asking Honda questions in the Spanish Honda forum that I normally do, not here, this topic is just a desperate exception.

Hugo

[UHJ200]

Dear Hugomez,

You do love to pose a difficult to solve at a distance problem don’t you?!!! You have my sympathy though; intermittent ones at any distance can be the absolute pits! At something like, (by my neanderthal navigational reckoning), 350 miles, it’s all but impossible but we can at least poke a stick at it!

Such “electrical sounds”, if indeed that is what they prove to be, must be pretty loud to be heard over the other noises made by a running engine, it would entail quite a bit of energy and would imply a high tension leakage which is the direction you have been going but then I'd expect some loss of power to show up at the same time if such was the case.

My inclination is to be suspicious of an electrical source, it may sound electrical but I am reminded of the classic half coconut shells used to make the “clip-clop” sound of a horse. Are you really sure there is nothing that could be setting up some sort of vibration that is dependant on engine speed and/or road conditions?

We’ve already got the “Sound of a Rumi” maybe you could post the “Sound of a Honda”?

My only other thought that the Jap guy that built the pesky thing must be getting pretty hungry by now so maybe it’s the sound of him rubbing his chop-sticks together? (Joke!)

[tony mooring]

Hugo We need a few more symptons!
Does the noise increase with engine revs?
Does it vary with the speed of the bike?Does the noise occur in all gears?
Try running the engine at night when it is dark and see if there is any "electrical arching" around the H.T. lead area.
Try changing the H.T. lead to a wire type.You may have a carbon lead which is breaking down.
Alternatively it might be the laughing shaft caught up with the whirlygig thus causing the gremlins to have screeming orgasms.
Tony.

[hugomez]

Hi David and Tony, first at all thanks to reply.

I checked that nothing was making the noise because the vibration of the engine, so we can rule out this possibility.

About loss of power, last week going by the highway at 90km/h the noise started going up and after around 2 kms the bike started loosing power, fortunately after reduce speed and keep the bike a constant speed of around 65/70 km/h the bike became to run well.

If when the bike is cold I start it and I ride smoothly, the noise take more time to appear, but if I ride at high rev appear faster. But this doesn't mind that only appear at high rev, once it appear even if I stop I can hear very clear the noise, then suddenly may disappear.

Yes, the noise can appear in any gear. Going fast or going slow. At high rev and low rev. (but as I said at high rev appear easily)

Tony I will try the wire type and see what happen. Also I will check in the night to check if I see some electrical arching.

The coil I ordered will arrive this week, I also will replace it to see what happen.

Cheers

[UHJ200]

Certainly beginning to sound more & more electrical. Keep us up to date with progress.

Doing it in the dark isn't a bad idea, it always was quite fun I seem to remember . . .

Mark you, some electrical problems can have their up-side, an intermittent coil was the root cause of me getting my Tipo for fourteen quid but on the down-side a loose Vincent HT lead earthing itself through my leg at 60mph on a dark pre motorway days A2 caused a bit of excitement at the time too!!!

[hugomez]

Yesterday having a ride the noise (as usual) appeared, then I stop to record it with my mobile phone but after listen it at home I decided not to upload here because the audio is terrible.

If I can I will try to record the audio with better equipment and upload here.

More news soon.

[Lasse]

Dear Hugomez - try to use "the omitting method" (to "take away" certain parts when driving)
Sounds dangerous?
Not really.
Here is what to do: Find a reasonable steep hill - with very little traffic - then drive to the top of the hill, (hopefully still having the strange sound, before proceeding downhill).
Go downhill, at good speed - say 50 Mph. - "kill" the engine - but REMAIN in 3.rd or 4.th gear! - Is the noise still there?
Alternatively (using a glove) do the same - lean forward, & rip off the ignition cap - does the sound then go away??

I am not personally sure it is a "electrical problem" - could be valves, cam lobes, cam followers - or worse, a broken oil-scrape ring.
Or, just a very simple thing (which infuriated me many years ago) namely a "loose" exhausts cylinder collar or gasket - making the motor have partially "acces" to the environment, bypassing the silencer - not so uncommon as you will think of!
It can, believe me, make a very sharp, "clicking" noise.

But, my recipee still is to "take things away while driving" (e.g. pull the clutch - change gear - try brakes and so on) but, offcourse - the bike need to have a fair amount of speed, downhill, to use the method...

Waiting to hear the results - or to have the adress to the Hospital, where to send flowers...

Have luck,
Lasse.

[hugomez]

Hi Lasse,

I'll try your method and see what happen, but I already have a little problem to do it here, ............................................WE HAVE NO HILLS IN AMSTERDAM!!!!!

I guess this mean I need to be even faster before to "kill" the engine. I'll try with the hope that nobody has to send me flowers to the hospital

[tony mooring]

Nah you won't need flowers Hugo! Rossi bounces well and he is a Spaniard!!!!!!!

[tony mooring]

Or is he Italian?????

[luckner]

Dear Hugo!
Sharing the doubt with other members of the forum that the noise could be not of electrical origin, I remember a case of a very similar ticking caused by a little peace of a broken piston ring, coming and going in the ring channel, obviously enlarging the hole and damaging the cylinder wall. I hope not to sound apocalipthic!
My other theorie that the ticking could be a aleathory grounding of a high tension spark escaping a defective wire, has no sense in this case if you as told have changed all the components of the ignition system.
Kind regards,
LUCKNER

P.S. In another order and to keep you friends updated, the running of my Rumi "Brrt" is improving as the motor becomes only little more time of use.

[hugomez]

Luckner, I keep the hope that the source of the problem is the coil (or the cable to the spark plug cap included in the coil). I'm still waiting for the new coil that I ordered last week, so I didn't replace it yet.

A broken ring piston, I hope not but if this is the source of the problem I will have to replace it, so I will learn how to do it (not everything is so bad)

Good that your Formichino's engine is improving bit a bit.

Tony, Rossi is Italian but ride the bike like an Spaniard

[Lasse]

Hugomez - I am certain about you will find the source of the noise by driving "with the rearwheel driving the motor"!
How can you do this, if there are no hills in Amsterdam??
Find an absolutely desolate, untrafficated stretch of road - employ a friend, a car, + 15 metres of rope.
Tie the bike with a socalled "slip-knot" to the centre of the handlebars.
The other end to the car.
Start VERY carefully - let your friend accelerate slowly, up to say 30-40 Kmh - with you onboard the bike - the bike in 3.rd gear - and WITHOUT the ignition on!
If you dont hear any noise now - then you know it is NOT an electrical problem.

If no noise appears - try to switch-on the ignition - but with closed fuel tap!
Then you will probably have some "life" from the motor - enough to decide if its a "blow-by" from the exhaust.
The motor will soon die - because it will not receive fuel, because of the closed tap.
Then you can go a little further - let the motor rotate, with "ignition on" - to determine if any unduly noise is coming from "electrical components"...

Towing a motorcycle - you must be mad!
Yes, maybe...
But, 48 years ago - my magneto became very muddy & wet - which rendered my 500cc 1952 Competition "Royal Enfield" without any sparks, following a "trials Competition" out in the open country.
About 20 Kilometers from home - late afternoon - wet & hungry - I attached a rope to my mates "Commer" van - and off we drove.
I reached home - without problems (no police interception!)
So it certainly can be done - but be carefull - not too much speed - and apply a "slip-knot" - just in case...

So, Hugomez - I believe you will learn about the eventual source of this nagging problem - if you let you drag.

Best Regards,
Lasse.

[Doubletrouble]

Hi ! first post here but I'm coming with a suggestion, based on horskjaer's idea but maybe safer....
just run the bike at a speed where this noise is clear and strong, preferably on a higher gear, then cut the contact for a few seconds with the gas still open and just hear if the noise disappears, is still there or changing....
this may help you to eliminate or confirm the electrical being the source of noise, something which I can't believe !

[luckner]

Hi Hugo!
Aha, if well understood, the cable is one part with the coil. Waiting for the spare onel, you can try a "farmer solution" enveloping the cable in any tough rubber or plastic hose, even a garden sprinkling one, after removing the cap.
About towing a motorcycle with a car... the first attempt to start my Formichino two weeks ago was with this system. Decades ago I wouldnt hesitate to push her until firing but now...
Good luck with your nightmare!
Kind regards,
LUCKNER

[hugomez]

Thanks to all of you for those suggestions!!!

Lasse, I liked more the idea of the hill, much more. The idea to tow by a car trying to reach 40km/h is not something that make me very excited. Don't misunderstand me, the idea is not bad, but right now I have not in mind anybody that I could trust to drive this car. (95% of the people I know in Amsterdam has no car and always use bicycle or low capacity motorbikes to move) The few that has car has not my full confident to let them to tow me and my little beautiful bike.

We have a new member!!!!!, Welcome "Doubletrouble" to this forum. I was thinking to do exactly what you are suggesting as a saver method of Lasse suggestion, probably is not as effective because the bike very fast would stop, but at the moment I think I will try this first. (Once the rain let me do it)

Lucker, I'll try this too

This is great, I have many suggestions to test, as I said the rain is strong those days so I'm not using the bike. The ticking noise never appear just starting the bike, I need to ride for a while then suddenly appear, so to test I need a non raining day. I'm looking forward to start.

Cheers!!!!!

[hugomez]

This morning the weather let me ride the bike to work, so in the way I tried a few times Lasse's test. Sadly I must say I that the clicking still sound when I turn off the contact key.

I could not hear very clear the sound today, but I would say that one of the times that was there I was riding 5th gear and I "killed" the engine turning the key, my feeling was that the sound remained there for a while.

Anyway I'll test it again with more time to be 100% sure. I want to hear the clicking strongly as sometimes happen and then cut the contact. But now I'm starting to afraid that something worst than a simple electric problem is the source of this noise.

I'll keep update after more tests

[Lasse]

"Killing" the engine means "killing" high tension to the sparkplug & coil.
So, Hugomez - its probably not a electrical problem?
Just go on!

Lasse.

PS - it might simply be a "semi-loose" exhaust

[hugomez]

Lasse, I'm sorry but I'm novice in all this and things that are obvious for you are totally unknown for me.

After you last comment I guess that killing the engine is not enough switching off the contact key. You said killing high tension to the spark plug & coil. Would be enough if riding the bike I remove from the spark plug the spark cap?

If this is not what you mean, please help me to understand what I have to do to kill the engine properly.

Sorry and thank for your patient.

[Lasse]

OK - your generator/flywheel magnet produce electrical current to the battery? (if you have such one??)
This can hardly produce any noise, i guess.

But by "switching off/killing engine" - you simply deprive the coil and the sparkplug of electricity!
(the low tension 6 volt (or 12 volt) from rectifier/battery - goes to the coil, to be "upgraded" to, say 30-40.000 volt high-tension - which in the end provide you with a spark, inside the engine...
There could be a noise here - but you write the noise goes away - without power to the coil/spsrkplug!

So, on you go...
Please look/listen to the exhaust where it leaves the cylinder (or feel, with your hand if any "blowback" is evident)


Lasse.

[UHJ200]

As I understand the most recent information switching off the ignition while the bike is moving, (engine no longer producing power), results in a continuation of the noises. If this were the case then it more or less rules out a high-tension leakage problem as there would be no energy going to the HT coil or lead.

If this bike is the same basic design as the 125cc Honda and they certainly look alike, then it will have an AC crankshaft mounted generator feeding the machine’s electrical system via a full wave bridge rectifier.
The engine will also have an overhead camshaft driven by a chain. Plenty of sources of noise there, there are at least seven components in the valve/rocker assembly alone not to mention the chain and chain tensioning system! Honda are fond of running the camshaft directly in the aluminium head, in the main this works well as long as it is well lubricated, if not bearing damage is inevitable and while the engine may still operate there is the risk of undersigned clearances developing that could result in vibrations and moving parts making intermittent contact where it should not.

On a more mundane level my vote is still for some sort of sympatric vibration as the cause. I particularly remember a fuel tank baffle causing such a problem; it defied identification for several years! Even progressive stripping of the bike might not work right away because the simple act of taking off parts might alter the “tuning” of the guilty part and stop its antics.

I have one other small “wind-up”. I think poor old horskjaer must thinking of his research on his Mk.99 DeLorean flux capacitor! ---------- 30/40,000 volts? More like 10/15,000 volts surely?

[hugomez]

Ok, I'll observe the exhaust once the noise appear again to see if the clicking is coming from there.

Because the coil that I ordered must arrive soon (hopefully tomorrow), I will replace anyway and then, if as David (UHJ200) has suggested the source of the noise is a vibration of one of the elements around (as for example a cables) , perhaps after remove everything around and mount again the noise disappear.

The cam chain was adjusted not long time ago.

I'll keep posting updates

Cheers!!!!

[tony mooring]

Hugo, I've been thinking!!!! If it is a ticking/buzzing sound which rises and falls with the engine revs, it could possibly be the cam chain adjuster slipper that is breaking up.Not a very difficult job to replace the cam chain tensioner but you will have to dismantle the cylinder head possibly. If it is that I suggest you also replace the cam chain.
Try and get a HAYNES manual,maybe on ebay, for your bike and things will be explained in there.

[UHJ200]

I think Tony might be onto something here, one of my technicians had a 125cc version that he commuted on and I seem to remember, (“seem” – 'cos we are talking 25 years distant!), had mysterious noises for some time before he discovered just the problem Mr. Mooring describes.

[Lasse]

A reproof to good old UHJ200...
(From the very old Horskjaer)
This Honda might have/probably have - a CDI charge ignition - so, 30-40.000 volts-peaks could easily be produced.

But, UHJ - I am tended to follow you in your thoughts - that some "hidden/wild" vibrations were the source of Hugomez´s agony.
I would recommend him to cast away his Japanese junk - and acquire a RUMI!
Because with a RUMI - he will never hear anything but the noise from the exhaust...

With respect,
Lasse.

[UHJ200]

Horskjaer,

Hmmmm! Still not entirely convinced although I do know the voltages can get pretty high because I once made such a unit from scratch, I even wound the special transformer. One day while under test it “got loose” on the bench – inch long sparks leaping from tool to tool! Needless to say the spectators and I retired to a circumspect distance until a 700v thyristor gave up the unequal struggle and we summonsed the courage to poke it with a stick to make sure it was dead!

If you must persist with these voltages I do happen to have some lead glass windows from a redundant electron microscope that you might care to stitch into your underwear to protect your, er, “delicate bits”!!!