YBR 125 engine noise in full colour

[WD Forte]

Just done some electrical work on this guys YBR125 and when I started it
didnt like what I heard much.
He bought a 2010 bike with a knackered engine so I fitted this one he'd bought that had done 20,000 ish about 18 months ago.

It sounded pretty good to me back then.
Now I estimate its done around 32000 and sounds a bit 'raw' to me maybe a bit 'cam chainy'?
not sure.
I might be a bit over fussy, maybe they all sound like that so want opinions

As phone cams dont always give good sound reproduction
I listened to the vid in vimeo then went and listened to the bike again.
The 'raw' 'chainy' sound is a bit more pronounced than IRL, but not too much

waddya fink?

https://vimeo.com/368308568
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bikers smell of wee

[Easy-X]

Just sounds rough to me. Does it have one of those plunger type jobbies for the cam tension?
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Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[WD Forte]

Just listened to a couple on youtube and this one
deffo sounds rough in comparison.
Is it a noisy cam chain or just worn out I wonder.
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bikers smell of wee

[stinkwheel]

You should be able the measure the camchain. There will be a tolerance for a certain number of pins listed in the workshop manual.

You could also try removing the tensioner, checking it's moving (or isn't at the limit of its movement, there will probably be witness marks of where it's sitting) then cleaning and resetting it. There will be a procedure for removing and resetting the CCT in the workshop manual.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[WD Forte]

He's taking it away in the morning and I usually only see it when he's broken something or wants something fitted.
I did mention I thought it sounded rough when he dropped it off yesterday and will tell him again tomoz so it's up to him really I spose.
If it were mine,I'd be looking into it
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bikers smell of wee

[BusterGonads]

I know its all about cost, but cam drive mechanisms are the Achilles heal of many otherwise excellent engines, cars and bikes. There are a lot of VW diesel lumps in scrapyards because of snapped belts. I like the idea of driving them with gears - like the Kawasaki W650 and W800 series. Failing that, having a gear driven cam shaft in the bottom end and using pushrods was a system that rarely gave any trouble.
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2023 Royal Enfield Classic 350; 2000 Honda CG125; 1997 Honda Nighthawk CB250

[stinkwheel]

[WD Forte]

As the guy was late picking up the bike 0 I whipped the tensioner out
to see if it was working ok
I didn't have time to remove covers to get it to TDC
for any in depth tests but hoped to get a rough idea of condition.

The tensioner appeared to function OK so measured the
depth between the tensioners mating face on the cylinder
to compare the depth to blade with full tensioner travel.

It was about 10mm short of full travel which without knowing
the position of the piston and valves suggests
that best case it's got a bit left
and worst case the chains in need of changing

It only came here to get a new front mudguard headlight and indicator
fitted but I try to keep him informed and give advice on looking after his bike
as he's an utter tech numpty.
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bikers smell of wee