GV 125 S Valve clearance

[Lokutes]

Bike Model = : GV 125 S

Hi all

When cold and warm I could hear the Valves “ticking”, so I checked the clearance and put in new Shims where needed.

Clearance is now 0,08 in and 0,10 out on both Cylinders, now the ticking is definetly quieter when cold, but when shes warm they are louder expecially at higher Revs.

Apperently 0.08 in and 0.10 out are the Values for the GV 125 S, so I was told in a Facebook Group and videos on youTube.

 

Its really annoying, did I do something wrong are is it normal for this Model?

First time Ive done Valve clearance using Shims, my old bike had Nut and screw, it was easier 😉

 

Thanks

Barry

[♠️ MARCEL]

Hey , if possible, upload a video to youtube and mark it as “unlisted” (means no one will find it on youtube)

Simply just paste the link here:

Make sure the phone or camera is away from the exhaust or too much wind , so we can hear you revving up and letting it idle for a couple of seconds.

While you do that, go to the engine with your ear and a screwdriver, poke the Tensioner with the pointy end of the screwdriver , then your ear on the other end , see if both tensioners make the same noises ? Or if you hear any chain slapping.

Also do the noises change if you pull the clutch IN (pull cable) and clutch OUT (let go)

The idea is to pin point exact noises where are most loudest and it would be the area to work on.

Yes clearances both cylinders:
Intakes = 0.08 (margin 0.01 = 0.07 to 0.09 is OK)
Exhaust = 0.11 (margin 0.01 for any feeler gauge inaccuracies as above)

It would be alarming if it was both 0.03 as no that’s way too tight of a clearance and would disappear when it’s hot. Just a bad day waiting to happen.

Do they sound like this ?
https://www.youtube.com/watch?v=GAWKHBycWvQ

Yes it’s a silly youtube video, but imagine that same ra-tat-tat-tat faster and more metalic higher pitched sounding, then i suspect either clearances or cam tensioner or chains , but if you’re wise enough to remember howw everything was installed, and record yourself ==> Remove the cams and check their bearings and cam-sprockets for any teeth damage.

[Lokutes]

Hi Marcel

 

Thanks for the tips…

When i pull the clutch the ticking is still there no changes, I rechecked the clearance using new gauges and found the intake to be too big, 0.10 to 0.11.

I ordered new Shims as I only had 0.05s, got some inbetweens, 0.025s

I now have 0.07 intake and Exhaust a tight 0.10, when shes cold I hear a faint ticking, which is normal, and warm only Audible at higher Revs.

Not as loud as before, I popped round to my local Dealer/Garage and he said sounds normal, so I guess its sorted.

 

I still find it funny that they are audible/louder when warm, normally the ticking should go away?

 

Thanks

Barry

[♠️ MARCEL]

I could judge (if i can) if you upload a nice video of the phone near the engine valves so we can hear if the valve chatter sounds OK or not. (try to get away from the exhaust as they are louder than the engine)

Try Motul 7100 oil. Probably the best oil Hyosung bikes can drink and it does help a little bit to calm down the sounds of the moving parts inside the engine (just a little bit!)
Plus your gearbox will love you.

Old ducatis are loud generally and have a dry clutch with adds to the ticking noises but it’s normal for it to sound like a “tractor”.

The GV125-S should have a small bit of valve chatter especially with the rocker arms hitting the tappet buckets , a bit of ticking will occur until its a little warmer and oil is fully circulated before riding off.

[Lokutes]

Hi Marcel

Sorry for the late reply, i finally got round to making a video

After i did an oil change,  with filter, i noticed the front manifold gasket was not ok, so i had an air leak, new gasket installed

It definitely sounds like the valves, not so much the front cylinder, the rear cylinder is definitely too loud, annoying when riding as i am sitting right on top of it.

Have a listen and let me know what you think

I used the selfie camera so the mic is right on the cylinders,  that’s why the video is mirrored,  and she at Temperature, warm

Thanks mate

Barry

[♠️ MARCEL]

I would say i prefer that noise than an eerie too quiet of a motor, as that silence kills so to speak but if the rattling sounds increase with revs in tandem , it suggests:
– one of the shims is too thin (clearances too wide between the cam lobe and bucket)

As the lobe presses down, and lets go ==> if the gap is too much, the bucket’s valve spring shoots it back up until meets the lobe again (almost like instantenous metalic fist bumping, if i can even describe that correctly!)

Cam Tensioner (as the hottest cylinder than the front) , this could be likely as the chain races up and down , the tensioner’s ratchet may be juddering or causing a chain rattle slightly but , you did not mention if the tensioners have changed their sounds from either front or rear or if they both sound identical ? So i will leave that for you to judge with a screwdriver on it and other side of the screwdriver on your ear.

– debris along the cam bucket and inside the shim itself, affecting final clearance figures or that the engine needs to be spun by hand a few more times ice cold to verify clearances before starting it.

Hope this helps!

[Lokutes]

Hi Marcel

Both Cylinders sound the same, no chain rattling or any other sounds out of the ordinary.

What I did was I measured the clearence again, this time I turned the engine a couple of times and measured again and again, Intakes were too big.

So I changed the shims, again ;), now she sounds right, ticking when cold and hardly audible when warm, so I am going to leave her as she is

 

Thanks

Barry

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