Does this sound off to you?



I feel like my bike sounds more like a lawnmower than a motorcycle when I rev it. Does anyone have experience with engine noise like this? It seems localized to the left cylinder. Any help is appreciated.

Sounds exactly like mine ('04 gs500f).  The ride is fine, and everything feels good to me, so I've assumed it to be pretty normal for the bike.

You mean that high pitched sound that goes louder the more you rev the engine (I think that after 5-6k rpm that sound stops, or maybe it is just drowned in the screams of the engine?)? Mine does that too, its annoying and I have no idea why it does it...

Check the valves. if its loose, you need to set em to spec, and don't use Chinese shims.
Check the cam chain for being tight between the cam sprockets.
If those are OK check for intake and exhaust leaks.

I hear a sorta tapping type noise. If its anything more serious than these 2-3 ... its not likely you can fix it without a full on rebuild.

Cool.
Buddha.

Yes, the tapping, metallic noise is something different(and probably something to worry about). I am talking only for that high pitched noise...

Loose starter clutch rattle at idle.

Hmmm, so is it supposed to do that sound only in idle? Because it does it even when it gets revved. It is shown in the video too  I am not talking about the metallic tap that is heard, just to be clear.

It seems to be in the whole rev range.
You could have a simple case of goats. Far better than the crank or rod bearing or counter balancer problems.
Cool.
Buddha.

Diagnosing faults by ear alone is difficult, diagnosing them by ear over the net is very difficult. Sounds can echo, reverberate and loose emphasis in the process. Its like me standing next to you, dropping my guts and saying guess what I had for dinner last night!!

Its all been done before..........You will get one person saying cams, one person saying valves, one person saying camchain, another saying tensioner, another saying loose clutch/slap/bearings until every possibility has been covered leaving you are non the wiser. The GS5 mill is far from being a quiet engine to start with even when in good order which complicates things even more.

Much better to get someone experienced to listen to it and attempt to pinpoint its source while actually stood next to it and then consider their opinion as a starting point.

Thanks for the replies.

What is a "case of the goats" lol?

I'm completing a restoration this week to get my bike back to my pre-accident operation. It made this noise the entire time I owned it. I think when I first took it to a mechanic right after buying it, when I was completely utterly ignorant of literally everything, he described it as a "Ping" noise.

Possibly related is the utterly smashed condition of the left sparkplug (I have since replaced):


After I complete a few improvements this weekend, I'm planning on doing some of what you suggested:

• Valve Clearances
• Valve timing
• Ignition timing

I can say that the bike ran "fine" during the 6 months of usage I got out of it last year. I never felt great about the noise, and my bike got 40mpg as opposed to the 50mpg that I've seen reported. I have to run it in PRI because the previous owner ruined the vacuum system (fixing that this weekend as well.

Basically, there's a lot of variables in play. Once I get the bike functionally operational, I'll do a more thorough inspection of the topend.

Something has caused the electrode on the lower plug to close up, they don't bend like that in normal use.

Possibly something has got in the chamber or broken off a valve/seat and hit the plug. I would be looking at a compression test and then pulling the head off for a good look.

I removed the fairing and managed to tighten the exhaust bolts a bit. One screw was somewhat loose, but the whining sound remains. I repeat that that its not a ticking or taping sound, just a high pitched whining, audible in the video too (in the video I think I also hear a metallick tick/tap, apart from the sound I am talking about). Is it possible that culprit is the cam chain being too tight? If it is, is it easy to fix?

This video really nails the hissing/whining I am talking about! So, any new diagnoses? 

EDIT: The guy that posted this video said that his problem was solved with a carb synch. Do you think its a possibility?

Quote from: bertreynalds on July 23, 2015, 12:41:34 PMWhat is a "case of the goats" lol?

When the magnets come loose from inside the alternator rotor, I believe the goats name for it came from Buddha originally.  If you check that also check for a loose starter clutch which is attached to the backside of the rotor.

Plug got "gapped" by the piston ... easy diagnosis and sorry bad news for you.

Rod bearing ... dead giveaway. It will actually run, albeit anemically and just a few miles ... but its done.

Cool.
Buddha.

You ran it for 6 months.
That's not a rod bearing. Someone gapped the plug wrong.
Set the gap right (or replace the plugs) and run it. You may have just 1 cyl not running due to shorted plug.

Cool.
Buddha.

Quote from: The Buddha on July 24, 2015, 07:17:52 AM
Plug got "gapped" by the piston ... easy diagnosis and sorry bad news for you.

Rod bearing ... dead giveaway. It will actually run, albeit anemically and just a few miles ... but its done.

Cool.
Buddha.

Does that relate to the video I posted? I've done around 400 miles, and that sound was already there. By the way both cylinders run, although the right one is a bit colder than the left when on idle. It is my first bike, I dont have much experience, but I wouldnt say that it runs anemically.... I did manage to get it to 115 miles indicated, and it does accelerate in a frightful manner when required 

Plug got dropped on the floor nose first.

Quote from: gsJack on July 24, 2015, 09:51:47 AM
Plug got dropped on the floor nose first.

Bertreynalds never mentioned that it got dropped... I think that is the way he found it when he got it out...

OK now, I got no clue man. If your plug was like that when installed in the bike - you must have had poor spark in that chamber. Bad enough to make a noise but not too bad to run No idea. But run it with nice new plugs and see.

If your plug good when installed and was hit by a piston to look like that - then your rod bearings are bad.

You did not make 400 miles on a bad rod bearing. You wont even make 4 miles. You didn't do 400 on goats either. More like 40 max before it quits making charge and dies in a nasty and fugly manner.

So if that noise was there all the time, my guess is you have wicked cam end float, sloppy valves or one ridiculous exhaust leak. These are all pretty tame compared to the first 2.

Cool.
Buddha.