Tuono 2003 engine tick, valve tapping noise.

Hi everyone.

Im trying to figure out a problem with my Ape and i hope that i can spark a discussion where seasoned tuono riders can maybe help me solve it.

Here it goes.

Bought a 2003 model Tuono 2015 summer with 35k km. Ran fine. Did the usual service (new tires, oil, filters, coolant etc). After 1000-1500km got a little ticking noise in the engine and it comes from the first cylinder. It progressed to quite nasty noise and at some point i didn`t have the courage to ride it anymore. Aside the noise, the Ape behaved very well. No drops in power or something like that. After much diagnosing i decided it could be the cam chain tensioners. The noise is not affected by activating the clutch and the noise rises with the revs. It is there all the time and specially when the engine is hot. The engine temp is normal.

Now, i decided to take the bike apart. Removed everything so i could get the tensioners out. Also took the valve covers off and checked the valves. They were in spec and everything seemed fine under there. No weird movement in the upper balance shaft and no excess play in the cam chain and no wear marks under the cover. The only valve that came close to being out of spec was the first cylinders exhaust valve (0.28mm) but it is still in spec so i decided it`s not worth taking it all apart.

After i pulled the tensioners i inspected them and it seemed that the first cyl one (where the noise came) was done, because it did not hold the oil so well as the other one (when i filled them, it didn`t get rock hard). I ordered a new one and after it arrived (took a MONTH!) i installed it (filled the tensioners with oil) with the new valve cover gaskets and finally put the bike together again. Also, i changed the oil with the oil filter. Before i used Motul 15w50 300v (full synth like the manual says), now i used Motul 5100 15w50 (semisynth). When i changed the oil, there were very few metal specks in it, no golden coloured only shiny metal ones but i emphasize on "very few". I think it`s normal.

After everything was double checked i started the bike. Everything looked fine BUT the noise was still there. It was quieter, but it was there. I got it to temp and let the fans come on for two times. Next time i took it for a ride. It behaved well on the street, not that smooth as before but that could be because i removed the throttle body and it needs now a sync. Im fairly sure that i didn`t jump any teeth when i was messing with the valves.

After the ride i inspected the oil level as i just changed the oil. I noticed that the level was too high and removed from the top a few syringe full of oil, but i noticed that the oil was totally foaming and the oil tank was truly full with foam. I have noticed this before with the old oil (full synth).
I have heard from mechanics that it is a possibility that the tensioners catches air bubbles from the foaming oil and this could affect the tensioners and thus the rattleing cam chain.

Now, im pretty frustrated about this. I really like the bike and i like fiddleing with bikes in the sheds, but my mind is totally empty and im on the verge of giving in to the "snake oil" business as i have laying around a Liqui Moly oil additive that promises to solve all my problems.

In retrospective:
The ticking noise came soon after an oil change (Motul 300v 15w50) with no power drops, bike behaved the same. Only the first cyl makes it.
Valves are in spec. No wear marks, no exsessive chain slack no nothing.
Changed one cam chain tensioner as it looked like it doesn`t function well.
Spark plugs are changed, coolant is changed, many pipes are changed, drive chain is tightened, oil is changed (Motul 5100 15w50).
The noise definitely comes from the front cyl and it isn`t affected by the clutch.

My questions are, what are the alternatives for the noise. What steps should i take? Any advice would be much appreciated as i want to solve it and let the "take it to the dealer" options be my last one. I think, the next on my to do list should be checking the oil pressure as the tensioners only work with a proper oil pressure but the pressure light has never come on.

Heres a video after a 15-20 minutes of riding. If you listen closely you can hear the difference from the the engine noise and the ticking sound. You can actually hear it quite well when standing next to the bike but my yoshimuras are pretty loud even with the baffled in it.

[video]https://youtu.be/q0nnyaFh0ZI[/video]

Any advice would be highly appreciated!

Hi.
Thanks for the replys.

No, im sure that the noise wasn`t there before. I know the engine has it`s quirks and is pretty loud, but when the sound appeared it was fairly small, but it progressed to that point where i decided i need to pull te bike apart in the middle of summer to find out if it`s a major problem. The only thing that gave me hope was that the bike appeared to be perfectly fine aside the noise. It did not have any power drops or anything like that.

I checked the airbox and a little oil was in it, i cleaned it and drained a little to prevent it from happening again.

I have tried the stethoscope method before, that is why im fairly sure the noise comes from the first cyl, but i will try it again to pinpoint the ecact place where the noise is dominant.

Im out of ideas right now and just wandering in the dark. Im getting a oil pressure reading this weekend to rule out any other possibilities.

4vr said:

sounds like a exhaust leak to me,

Click to expand...

What do you mean by that? You mean that the exhaust pipes have a leak somewhere? I havent thought about that, so i will check and rule it out.

The cam chain tensioner is changed. Is it even possible that the new one doesn`t work also or needs more time to work properly. I prefilled it with oil before i installed it.

4vr said:

there are copper gaskets between the head and manifold, looking at the heads on the vid i can see corrosion, leaky header or joint can sound like a tick!
on another note, it may be the injectors your hearing,

Click to expand...

Thanks for the tips. I will check them both and pinpoint the sound again to exactly where it`s coming from.

At this point im starting to second guess mself. Maybe it`s a good thing so i will check the basics again.

Will let you know if i find anyting.

PS: Is there any other way to check if it is the fuel injector thats causing the noise beside just pinpointing the location of the noise?

4vr said:

on another note, it may be the injectors your hearing,

Click to expand...

Hi again.

I had some time to check your tips and i think i made some progress on finding the problem.
I pinpointed the noise location as close as i could. Took my time to do it thorougly and i think you were right about the injectors.

I checked both the cylinders at various areas and didn`t get the rattle/tick noise i hoped to get, but i did found out that the injectors were making this kind of sound, especially the right side injector. It matches the engine revs as it lowers and rises when i open the throttle. Im a little confused about this as i can hear it loudly when im standing on the right side of the bike and i could swear it comes from the first cylinder when i have my ear close to it but if i use the stethoscope on the cylinder i can only hear swirling sound and no tick or knock or rattle but when i use the tool on the throttle body and on the injectors i can hear the tick loud and clear. So, i conclude that the noise is from the injectors.

As i said in the first post, that after i installed the cct the engine was much quieter, so i think the cct was faulty as well probably due to the fully synthetic oil and old age. But after the installment i could hear the ticking sound from the injectors because i was LOOKING for a noise. Maybe the noise was there before, im not certain.

I checked other things as well like the copper gaskets of the manifold and bolts and details that could rattle and didn`t find anything else.

Now that im a step closer to solving the noise issue, what are my options? I checked the repair and workshop manuals and it only shows how to dissassembly the throttle body which is useful, but can i just unscrew the injectors without removing the whole throttle body?
Is there a way to clean the injectors so they would be quiet again or should i just buy new ones? Are there even injectors to be sold without the throttle body?

and thank you again for the tips, i was so fixeted on the engine that i didn`t consider other possibilities.

Paul D said:

I'm not aware that injector noise can be stopped, other than replacing them. So if they ain't broke don't fix them (I.e. leave be until engine fails to run properly.

You could always try a bottle of injector cleaner and see if that has any effect on the injector noise.

Sounds like your in the right area though.

Click to expand...

Well, i did some research and found out that when an injector gets suddenly particulary loud it could mean that it`s days are numbered.
I will take them off and send them to a shop where they clean them with ultrasound and test them. It costs only 10 euros for one. If all checks out i will install them and see if it made any change and report back here.