Valve Clearances - when to do?

[ulysses_sc]

4 stroke bikes will need valve clearance checks and/or adjustments periodically, regardless of engine size. Best approach is to follow the manufacturer's recommended intervals. Tight valve clearances do not make any noise, while loose clearances will make a tapping noise. However, loose clearances are no where near as critical as too tight, as too little clearace may result in burnt valves.

[plasticprison]

hmm.. looks like i'm heading down to get my valve clearance done this week, since govt is sponsoring the cost. lol.

 

anyway, while on the topic of valve clearance,how come some mech don't see the need to do valve clearance for bikes?

[Pandoras Kitten 3]

anyway, while on the topic of valve clearance,how come some mech don't see the need to do valve clearance for bikes?

 

Good question, I would like to ask the same for why almost all mechanics love to inflate my Phantom tyres to 260-280kpa when the optimal performance and handling comes from 200kpa (anything more is a major skidding and tyre wear hazard!). Yes I know the sidewall of the tyre says 260kpa max load and it's a Class 2 sized tyre but it's a 160kg ultralight cruiser. Common sense that Honda specifies to underinflate deliberately for more grip, right?

 

... why nobody seems to adjust the carburettor air correction screw to prevent lean running conditions (engine will overheat at 100+kph on a 2B bike!) at highway speeds

... why no mechanic seems to think it a good idea to optimise bike gearing to the rider's style to save engine wear and decrease fuel consumption

 

... and it's probably the same for valve clearance. Outside of warranty service which demands the service provider follow the manufacturer's maintenance procedure, VC may be seen as "unnecessary" most of the time because improper valve clearance does not result in a bike-killing scenario. Don't touch = less work? There are some mechanics who I will not name that claim that major problems such as backfiring is because "CHOPPER IS LIKE THAT ONE!!!"

 

And of course when things fail due to overheating and other reasons, in part due to improper gearing, tuning, and clearances, an overhaul = more profit.

 

Not making any negative commentary here but it kind of encourages me to do my own research and manage my own vehicle. After all, an F1 driver, like an aircraft pilot, knows exactly what the machine needs and how its performance should be (in F1 the driver is an integral part of RnD too).

[plasticprison]

Ah.. i see now. i'm all for prolonging my engine life. If only i can DIY. Lol.

[MrIce]

I don't really recommend to follow manufacture interval of checking clearance, that abit too early to check for valve clearance. i would more recommend on 80k, u can check around other country's forum alot of them do it at much more higher mileage

[plasticprison]

My bike currently stands at 82000km I'm thinking of doing it at 90000km for a major service. I occasionally hear some ticking sound, it shouldn't pose any problem yet right

[crazydj]

My manual says that my bike's valve clearance must be checked and adjusted every 6000km. Do you think this is abit too much?

[Pandoras Kitten 3]

My bike currently stands at 82000km I'm thinking of doing it at 90000km for a major service. I occasionally hear some ticking sound, it shouldn't pose any problem yet right

 

No it won't be a major issue but once valve clearance is done, the bike will feel very different in a good way!

 

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[nx.]

4 stroke bikes will need valve clearance checks and/or adjustments periodically, regardless of engine size. Best approach is to follow the manufacturer's recommended intervals. Tight valve clearances do not make any noise, while loose clearances will make a tapping noise. However, loose clearances are no where near as critical as too tight, as too little clearace may result in burnt valves.

 

hmm 4 stroke ? Should i do for my wave? meter hitting 90k.. will it be any much difference?

[Pandoras Kitten 3]

If your Wave has issues with starting and feels like it's getting sluggish in acceleration, it might be good to do a valve adjustment. If it runs fine then leave it - but at your next "full servicing" session it's no harm getting the mech to look at the valves since the bike is going to be there for a while.

 

Valves that are out of operating tolerances do get noisy, and that would mean the matter is urgent. I presume your Wave is still 'healthy'

 

90,000km is a relatively long period of time and I believe the valve clearance checks are placed in the Honda warranty service manual for a reason - these little things do go out of alignment very gradually because if you're riding at say, 6,000 RPM, the exhaust and intake valves are moving 100 times a second!

 

If no parts need replacement in the valve assembly, an honest bike shop like Planet Motors knows how to adjust the valves very quickly and charge a low, low price for a single cylinder 2B.

[gohjohan]

My manual says that my bike's valve clearance must be checked and adjusted every 6000km. Do you think this is abit too much?

 

That's even more than Ducati. You sure about every 6,000km? Ducatis have Desmosedici valves and those are run by belt. That's why every 10,000km have to do valve clearance.

[crazydj]

That's even more than Ducati. You sure about every 6,000km? Ducatis have Desmosedici valves and those are run by belt. That's why every 10,000km have to do valve clearance.

 

http://i945.photobucket.com/albums/ad291/crazydj_sgbikes/PeriodicMaintenanceMinorRepair.jpg

 

It says 6,000km right? So what does this mean?

[quikslvr]

I'm surprised to hear about valve clearance on phantom.i thought valve clearance is only for cl2 bikes..

[Phang]

My first DIY valve clearance adjustment was on my Honda Cub C65

 

Got change from surprise to shock or not?

 

http://pdfresh.com/wp-content/uploads/2011/03/honda-c65-vehicle-image-view-2.jpg

[ulysses_sc]

I'm surprised to hear about valve clearance on phantom.i thought valve clearance is only for cl2 bikes..

 

4-stroke engines are fundamentally the same, regardless of capacity, cooling method, number of cylinders, etc. All rely on valves and cams (let's not discuss rotary engines). All will need checks and adjustments sometimes, some more frequent than others.

[Phang]

There is an exception, engines with hydraulic lifters/tappets don't need valve clearance checking/adjustment

[ulysses_sc]

There is an exception, engines with hydraulic lifters/tappets don't need valve clearance checking/adjustment

 

Yeah, Harleys and some big twin Hondas use hydraulic lifters, but these are less common compared to the "normal" screw/tappet and shim under bucket.

[Phang]

Come to think of it, actually it is the other way round. Most bikes fitted with maintenance free hydraulic lifters/tappets are Class 2 bikes. It is the smaller capacity 4 stroke engine motorcycles that cannot escape from valve clearance checking/adjustment.

[World Misanthropy]

So after reading all the posts here, my vtec-3 when start engine cold, got slightly tick tick sound but when engine hot, no more sound liao.

 

So i guess its ok yeah?

[gohjohan]

http://i945.photobucket.com/albums/ad291/crazydj_sgbikes/PeriodicMaintenanceMinorRepair.jpg

 

It says 6,000km right? So what does this mean?

 

Check if the valve needs adjustment and if it does, adjust accordingly.

[gohjohan]

Come to think of it, actually it is the other way round. Most bikes fitted with maintenance free hydraulic lifters/tappets are Class 2 bikes. It is the smaller capacity 4 stroke engine motorcycles that cannot escape from valve clearance checking/adjustment.

 

Mine still needs valve clearance but every 40,000km

[Pandoras Kitten 3]

Some things to read about valve clearance over Vesak Day

 

Valve Clearance on BMWs

http://w6rec.com/duane/bmw/valve/index.htm

 

Yamaha ATV

http://forums.atvconnection.com/yamaha/201037-yamaha-bruin-valve-adjustmet-how.html

 

Camshaft design (nice diagrams)

http://www.motorcycleproject.com/motorcycle/text/cows-clear.html

 

"Are valve clearance checks important" - GS500 forum

http://gstwins.com/gsboard/index.php?topic=8633.0

 

Yep, valve do need checks and regular setting even on a new bike, and how to do it in video format:

 

[video=youtube;yNJ9Da2dF-Y]

Edited May 17, 2011 by Pandora's Kitten :3

[Pek88]

Guys.. I went to planet motors to do valve clearence for my s4.. He asked me y i wanna do valve clearence so i say i nvr did it b4 n my mileage is oredi high, he den says s4 deres no nid to do valve clearemce.. Bt i was abit itchy n hv xtra cash so i say den do timing chain for me.. He den hear my engine n says theres no need to do timing chain also bt if i really wanna do den he will do timing chain together w valve clearence.. Guys.. Im confuse, so is there a need for our s4 to do valve clearence.. If its so which bike shop cn do it n roughly arnd hw much?.

[plasticprison]

Guys.. I went to planet motors to do valve clearence for my s4.. He asked me y i wanna do valve clearence so i say i nvr did it b4 n my mileage is oredi high, he den says s4 deres no nid to do valve clearemce.. Bt i was abit itchy n hv xtra cash so i say den do timing chain for me.. He den hear my engine n says theres no need to do timing chain also bt if i really wanna do den he will do timing chain together w valve clearence.. Guys.. Im confuse, so is there a need for our s4 to do valve clearence.. If its so which bike shop cn do it n roughly arnd hw much?.

 

heheh. ah chong say no need then just leave it la. how much did he quote you for the timing chain and the valve clearance?

[Pandoras Kitten 3]

When to do valve clearance?

 

Two options - one is just leave it if the engine sounds right. Can't guarantee max efficiency over a long period of time. Waiting for the valves to become noisy (obviously out of tolerance) may have risk of engine damage or running with lower than normal efficiency. If engine seems to lose fuel economy over a period of time this may be one of the causes.

 

Second is to imitate the manufacturer's warranty service schedule and do checks on the valves to keep them within spec, and this will keep the engine running at optimal efficiency. I'm currently creating such a "warranty service" procedure for myself, checking valves/timing chain every 10k km or so.

 

My Phantom was running on the same timing chain & tensioner for over 60,000kms and valve clearances more or less, never. Ran much better after doing VC. Was cheap and fast at Planet.