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Hello all,

I purchased a pre-owned 2011 Yamaha Fazer a few months ago.
The bike has done approx 30,000km.
While running the bike under load, there's a definite knocking sound from the engine that's audible till 4,000RPM, post which it reduces considerably.
The noise is more audible after the engine has warmed up than when it's cold.
I've attached an audio file of the noise as well.

When I handed the bike for a service to the local Yamaha service center (right after I purchased it from the first owner), they were very impressed with the condition of the bike and felt that I got it for a real bargain (₹34k excl. RTO expenses). The mechanic said the engine was unopened and said the bike was well kept.

Now, the ASS guys keep telling me over and over that the bike is fine. I showed them the noise clearly (we even went for test rides on my Fazer and another one they had in for service) and they even admitted to hearing the noise which was not present in the other bike. But they said this is normal and discouraged me from getting the engine opened. (I got the impression they were almost scared they couldn't put it back together).

My mechanic who services my other vehicles said he can open it up and fix it himself.

My question for all the experts here: do I need to open up the engine at this point, considering that I just purchased the bike? I would surely like to avoid the expense, but if it's going to ruin something else in the engine, I want it out of the way now.

Bear in mind that the bike has done a genuine 30,000km only, and the rest of the bike works flawlessly. There's no spark plug fouling, there's no smoke from the exhaust, and I get a fuel efficiency of 45km/l, something even the first owner didn't get when he owned it.

So is it necessary to open up the engine, in your opinion? Except for the noise, there are no obvious problems right now.

Thanks!

[MT_Hyderabad]

Originally Posted by ads295

So is it necessary to open up the engine, in your opinion? Except for the noise, there are no obvious problems right now.

Congratulations for your purchase.

I have the very same bike from the very same year. It has run 23 or 24k kms and is being rarely used.
I haven't heared the sound file you shared, but understand your problem.

Use a good company 20w50 engine oil and the sound will reduce.

The manual prescribe 20w40 or 20w50 oil.
The soil may be coming from the valves or the timing chain. As you have recently bought it, you are over cautious, continue to ride it for a few thousand kilometers and see if the sound increases.

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Hello

Well, if you listen carefully to the audio file you'll definitely realise that the pinging sound doesn't sound like it's coming from the valves or the chain...

The first owner doesn't have the owner's manual so I'm kinda stuck there, but the ASS replaced the oil so I'm sure they used the proper grade (I'll check again though).

The other diagnosis I've heard is carbon buildup in the engine. This is a real possibility but the ASS guys are afraid it's due to crankshaft/conrod bush wear and thus it could be an expensive fix... But even to clean up carbon deposits, the engine will have to be opened up.

I tried using some additives and obviously those only were for cleaning the fuel system.

One last option perhaps is to use an engine flush, as that may clean up the innards somewhat. This is admittedly not a real solution and I've also heard that it shouldn't be done just for the sake of it since things have a very real chance of going south, too, with an engine flush.

[Suresh Stephen]

If the bike is not consuming oil and there is no lack of power, I suggest you run it as is. Avoid opening the engine. You can avoid running the bike at the RPM range where it is creating this sound. One possibility is that the bike could be running lean. Try a re-tuning and make the bike running slightly rich. it may consume more fuel, but it will run cooler and you can possibily get rid of this noise

[Sran]

That's the sound of crank gone bad. Change the set. It will hold for 3-4000 kms.

[tarmacnaut]

The audio file you had shared sounds similar to the noise mentioned in this video. The bike in the video is a FZ v1 which has the same engine as your bike Fazer.

The knocking noise seems to be caused by a slack timing chain which can be easily adjusted with just a screw driver, which the youtuber explains in this video.

I used to follow this youtuber, who shares many practical tips for bike maintenance. His videos are usually thorough and spot on. Hope this helps

https://www.youtube.com/watch?v=qs-uQsi6zvk

[advstreak]

Originally Posted by ads295

Hello all,

While running the bike under load, there's a definite knocking sound from the engine that's audible till 4,000RPM, post which it reduces considerably.
The noise is more audible after the engine has warmed up than when it's cold.

Thanks!

Originally Posted by tarmacnaut

The knocking noise seems to be caused by a slack timing chain which can be easily adjusted with just a screwdriver, which the YouTuber explains in this video.

I have just recently replaced the Timing chain tensioner on my Hornet 160 at like 42K Km approx.

https://photos.app.goo.gl/v16M6kDA9eMbMRu78
Here is what my bike sounds like with the faulty chain tensioner. It has intermittent kit-kat noise at ideal and increases as the RPM increases.

In my case, it was more prominent with a slightly warmed-up engine.

I hope this helps zero down if it's a timing chain issue in your bike.

[John P Daniel]

It sounds more like slight tappet noise or timing chain slack. Check the valve clearances for the inlet and outlet valves when the engine is properly cool. Also check the timing chain tensioner for proper operation.

Clean the spark plug and check it's electrode colour as well. If it's anything white/black, the engine needs re-tuning as well. Opening engine is not suggested unless necessary.

[vedirah]

Originally Posted by ads295

Hello all,

While running the bike under load, there's a definite knocking sound from the engine that's audible till 4,000RPM, post which it reduces considerably.
The noise is more audible after the engine has warmed up than when it's cold.

Hey! Congrats on your purchase. Could you confirm if it is the fuel injection model (i.e. V2)? I suspect tappet noise. I had a similar problem with my FZ-S V2, and the mechanic refused to open the engine. He denied that anything was wrong with the engine. That's when I went to a FNG and asked them to check the tappets. As it turned out, some bolt was loose in the tappet mechanism/rocker arm. If something is loose in that linkage, the rocker arm tends to overshoot it's position every time it is actuated, hence the repetitive noise. They replaced the bolt and it solved the problem.



I advise you to go to a well known FNG and get this checked. If it's a FI model, it is highly unlikely to be engine knocking. I would first check for tappet noise, and then check timing chain. Usually the timing chain assembly on these engines is good for ~50k km.

[bkc]

Before opening, if there is any one way clutch, check that. I had a similar issue in my ss125, it was one way clutch, not tappet or timing chain.

[ads295]

Namaskar to all and thanks for your suggestions. I will check them out one by one and revert. I did not know it could be a timing chain issue.

@Vedirah: My bike is carbed, not FI. However, I will get the valves and timing chain checked.

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Originally Posted by tarmacnaut

The audio file you had shared sounds similar to the noise mentioned in this video. The bike in the video is a FZ v1 which has the same engine as your bike Fazer.

One thing I've observed, is that the video shows noise right when the bike is idling. My bike does not give any noise when it is idle - it makes that noise only when under load, and I mean like riding load (it also won't appear if I rev it in neutral). The noise is more prominent under higher load i.e. going up an incline.

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Originally Posted by MT_Hyderabad

The sound may be coming from the valves or the timing chain. As you have recently bought it, you are over cautious, continue to ride it for a few thousand kilometers and see if the sound increases.

It has now done 4,000km with me and the noise is the same as it was the day I bought it from the first owner.

[subincb]

Did you check the timing chain tensioner? If there is no smoke and no power drop you can rule out valves but if timing chain tensioner spring has a problem then valve could be making the noise. The tensioner screw is easy accessible. Why not check that.

[ads295]

Namaskar to all.

Time for an update.

I got the engine opened by my trusty mechanic. There's good news and there's not-so-good news.
1. The timing chain looks fine
2. The exhaust valve and engine head are all coked up. We'll clear out the carbon from there.
3. The piston is clearly worn and is past it's prime
4. The block looked OK, nothing major there.
5. No excess play observed between the conrod and the crank. This comes as a big relief.
6. The intake valve was loose in the valve guide that's in the engine head.
7. The worn piston was allowing oil to creep up into the combustion chamber. Even the intake valve stem was coated with oil (you can check the pictures, the whitish coloured valve is the intake valve). The place in the engine head where the intake valve is, also shows oil stains.
8. The camshaft rocker pin had above average play. Pictures show wear, too.
9. I measured the camshaft lobes and saw that they were within spec. No surprises there.

All said and done, we are replacing the below:
1. Valves
2. Carburettor slow and main running jet screws
3. Piston + rings
4. Camshaft rocker pin

Everything except the piston is ordered through Yamaha direct.
Why not the piston? Well, my mechanic says that the block is fine and Yamaha will only sell you the piston+block as a pair. I told him several times that I didn't mind the expense (it costs only ₹3300 for an entire set) but he said he can bore out the block a little and put in a new piston. So that's what we're doing, it costs ₹800 or so and is "Goetze" brand (Federal Mogul). His word is as good as gold when it comes to this so I don't push.

The Yamaha spares will be here by the first week of April (and I thought only Kawasaki spares took time! I ordered them around the 10th of March)

I'll keep you all posted on what happens next.