Valves adjustment – too tight?

[TomaszG81]

Bike Model = : GV125S 2022

Hey Guys,

I need your advice regarding valves. I just bought the bike and I’m checking the valve clearance. I think it’s way too tight as I can push barely 0.05mm 🙁

They way how I check it is the following:

I turn the engine until TDC (ex Rear):

I ensure it’s really on TDC (vertical line):

and then I check the lash. I can barely put 0.05mm only, through exhaust valve (intake is even tighter):

it’s like this on both cylinders. In the service book, there was a first dealer service at 1000km (so they probably set the valves)

I’m very surprised and confused as the bike runs just fine, starts like a charm, has acceleration and doesn’t overheat. Am I doing something wrong?

One thing I noticed is a strange color on the tips of the rocker arms… what could that mean…?

Please let me know what do you think. I’m ready to change the valve shims to make the proper clearance but wanted to double check with you first

Thanks

Tomasz

[♠️ MARCEL]

Take a quick look at this topic below, as i did post some clearance values:

GV 125 S Valve clearance

Also , report back to this thread when you spin your engine 10x , then recheck clearance, it might change 0.05mm to 0.07mm , although let the bike cool down overnight and do it on a cold morning as heat does affect the clearances.

If the markings inside the engine look like pen-markers like the green one, that’s what Hyosung did during production, as long as nothing looks broken.

[TomaszG81]

♠️ MARCEL wrote:

Take a quick look at this topic below, as i did post some clearance values:

GV 125 S Valve clearance

https://hyoriders.club/forums/topic/gv-125-s-valve-clearance/embed/#?secret=QXbF27h6tQ#?secret=248HWE90L9 Also , report back to this thread when you spin your engine 10x , then recheck clearance, it might change 0.05mm to 0.07mm , although let the bike cool down overnight and do it on a cold morning as heat does affect the clearances. If the markings inside the engine look like pen-markers like the green one, that’s what Hyosung did during production, as long as nothing looks broken.

Quote

 

Thanks Marcel,

The engine is completely cold. Clearance is way too tight (0.03 on intake and 0.04 on exhaust) so I need to replace the shims.

I was able to move the rocker arm sideways on rear cylinder but I’m not able to move the rocker arm on the front cylinder (exhaust one is stuck, intake can be moved).

What’s the tip to move the rocker arm? I tried TDC and also every other position of the camshaft but it’s not moving sideways 🙁

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