The workshop manual specifies clearances and adjustment intervals.

When a valve gets too tight it can cause hard starting, particularly when hot.

It can create a lean condition which makes overheating the engine a possibility.

Or it can get so tight it causes the retaining collets to fail and a valve falls into your engine and the piston hits it, making lunch of the rest of the motor in the process.

Quiet valvetrains can be more indicative of an issue than noisy valvetrains.

The point is that, whatever about the habits of lazy shops and owners, it's cheaper to prevent a failure than to remedy one.

whatwat wrote: ↑Tue Sep 24, 2019 6:29 pm What’s Akira?
I agree to a degree but I don’t think that logic applies to small capacity scooters/motos. I doubt any motos you see on the road in Cambodia have ever had the valves checked.
I just checked my user manual (Yamaha) and it doesn’t even mention if and when.

True for bigger bikes - say 200cc and up - but then it’ll be obvious because the bike probably won’t start or run rough. Usually the gap closes up not loosens so you’ll often not hear a tapping noise.

I don’t think having incorrect valve clearances means engine failure full stop. Maybe over many months it’ll wear the cylinder bores due to wrong mixture or burn the valves/seats out but that would be easily fixable.
The ethos here is don’t fix it until it fucks up.

My Yamaha user manual for a Jupiter states valve clearences should be checked at 1000 km then every 4000 or 1 year whichever the sooner

Kuroneko wrote: ↑Tue Sep 24, 2019 7:12 pm

whatwat wrote: ↑Tue Sep 24, 2019 6:29 pm What’s Akira?
I agree to a degree but I don’t think that logic applies to small capacity scooters/motos. I doubt any motos you see on the road in Cambodia have ever had the valves checked.
I just checked my user manual (Yamaha) and it doesn’t even mention if and when.

True for bigger bikes - say 200cc and up - but then it’ll be obvious because the bike probably won’t start or run rough. Usually the gap closes up not loosens so you’ll often not hear a tapping noise.

I don’t think having incorrect valve clearances means engine failure full stop. Maybe over many months it’ll wear the cylinder bores due to wrong mixture or burn the valves/seats out but that would be easily fixable.
The ethos here is don’t fix it until it fucks up.

My Yamaha user manual for a Jupiter states valve clearences should be checked at 1000 km then every 4000 or 1 year whichever the sooner

“Checked” is slightly different to adjusted. As I’ve stated there’s large tolerances in these small sub 125cc engines.

whatwat wrote: ↑Tue Sep 24, 2019 8:50 pm

Kuroneko wrote: ↑Tue Sep 24, 2019 7:12 pm

whatwat wrote: ↑Tue Sep 24, 2019 6:29 pm What’s Akira?
I agree to a degree but I don’t think that logic applies to small capacity scooters/motos. I doubt any motos you see on the road in Cambodia have ever had the valves checked.
I just checked my user manual (Yamaha) and it doesn’t even mention if and when.

True for bigger bikes - say 200cc and up - but then it’ll be obvious because the bike probably won’t start or run rough. Usually the gap closes up not loosens so you’ll often not hear a tapping noise.

I don’t think having incorrect valve clearances means engine failure full stop. Maybe over many months it’ll wear the cylinder bores due to wrong mixture or burn the valves/seats out but that would be easily fixable.
The ethos here is don’t fix it until it fucks up.

My Yamaha user manual for a Jupiter states valve clearences should be checked at 1000 km then every 4000 or 1 year whichever the sooner

“Checked” is slightly different to adjusted. As I’ve stated there’s large tolerances in these small sub 125cc engines.

Yes they check them to ascertain if the clearances are correct and if they are not they adjust them to the correct value. ie check clearances means check and adjust if necessary.

Kuroneko wrote: ↑Wed Sep 25, 2019 9:40 am

whatwat wrote: ↑Tue Sep 24, 2019 8:50 pm

Kuroneko wrote: ↑Tue Sep 24, 2019 7:12 pm

whatwat wrote: ↑Tue Sep 24, 2019 6:29 pm What’s Akira?
I agree to a degree but I don’t think that logic applies to small capacity scooters/motos. I doubt any motos you see on the road in Cambodia have ever had the valves checked.
I just checked my user manual (Yamaha) and it doesn’t even mention if and when.

True for bigger bikes - say 200cc and up - but then it’ll be obvious because the bike probably won’t start or run rough. Usually the gap closes up not loosens so you’ll often not hear a tapping noise.

I don’t think having incorrect valve clearances means engine failure full stop. Maybe over many months it’ll wear the cylinder bores due to wrong mixture or burn the valves/seats out but that would be easily fixable.
The ethos here is don’t fix it until it fucks up.

My Yamaha user manual for a Jupiter states valve clearences should be checked at 1000 km then every 4000 or 1 year whichever the sooner

“Checked” is slightly different to adjusted. As I’ve stated there’s large tolerances in these small sub 125cc engines.

Yes they check them to ascertain if the clearances are correct and if they are not they adjust them to the correct value. ie check clearances means check and adjust if necessary.

This is what I’m getting at. I don’t buy into the “drive it until something breaks” mentality. Per the manufacturer, certain PM items are recommended to prevent problems and get the most life out of the engine. It’s an investment, I don’t see the logic in just ignoring it.

I've had my honda 125 cc wave for 8 years, 28,000 kms, ONLY thing i have done to the engine is change the oil every 3,000 and changed the spark plugs once...
Great Bike

Valves on bikes and cars should always be checked/adjusted if needed..... stone cold

We've had our Honda Cub for over 20 years. I don't know how many exactly because my wife was driving it before we met. Changed the engine for a rebuilt. Each time cost us $75. Well worth it. I forgot to add that it has been replaced twice. I have no idea how many kilometers. it has since the odometer is broken, but hundreds of thousands.

I swear I looked to see if this was a thread I created a year ago.

I went through the exact same issue 1 year ago with my Click with 30kh/m. I worked for Honda in the US and I feel they would be disgraced to see how their customer service is represented here.

Anyone- as you know you cannot "hear" a valve out of spec .001". Most don't know what you are talking about. I couldn't find someone to check it. Honda's are so cheap you can drive them into the ground here and a rebuild is around $50. however, after my Click (no problems, upgrade) I found Dara motorcycle. he checked the valves and adjusted the carb on a little Aprilia for $25. he completely understands preventative maintenance. it's extra business for the businesses to educate the locals about this too.

A lot of the Cambodians dont know.

You can tell them what you want done, and you will pay for it. They think they know better, will do what they want, and will refuse to do what you want.

Then they will argue that they are right. They will never change their mind, as that would be losing face.

There are good and bad mechanics. Some do things you would have to teach a 10 year old not to do.

If your bike has done 30k then it is pretty close to needing a new camchain. they have a service live of 30 to 50k depending on the bike. A worn cam chain will eventuall alow the cam to jump or the chain will break causinf potentially fatal engine failure and fatal for you if you are going at speed. a loose cam chain will make a noise very similar to loose valves.
Changing the cam chain tensioner for a new one with a fresh spring may quieten the engine down and hide the symptoms for a while, but is not a long term solution. khmer tend to replace cam chains with cheap copies which usually stretch like knicker elastic and are done at 10k 9 what t do you expect from a $10 chain?).
Vlave clearances are usually set cold IN COOLER CLIMATES. the problem with hot places like Asia is the engine runs hotter, the metal expands more and you wind up with no clearance. if the clearance in the manual is .10 to .30 you would generally adjust it to the wider clearance for here, especially if you are running in traffice a lot. The narrower clearances are for cooler places. Inevitably running wider clearances increases enine clatter.
Finally automatics have drive belst and rollers which need replacing generally around 12 to 15k. If you dont the belt may snap and can lock up the back wheel. These toothed belts have a design life in km and time as the material they are made of degrades. generally its like 12k or 2 years.
So, bugger adjusting the cams, repalce the cam chain and the clearances witl be adjuted during this process, and check the drive belt and replace if necessary. At 30k you may also need clutch repair, depending on how hard its been run. small autos are commuting machines and not designed for long, frequent trips.
of course this is cambodia, so feel free to run it into the ground.