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Need Help Valve Noise after Valve Clearance

Mhmd

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Hello, new forum member here. Apologies if I posted this to the wrong spot; I'm still learning my way around.
I Purchased my 2014 nc750x almost a year ago with 44,000 KMs. ( i have 55,300 kms now ) it wasn't that well maintained but in a very good shape except for the suspension.
As I'm doing everything by the book i decided to check the valve clearances that are well overdue.
I did everything how it supposed to be and took me some long hours ( first time doing this kind of jobs ) I took my time doing it and took my time to understand all the mistakes on Youtube and maybe the misprint on some of the service manuals.
TDC, 360 degrees when no clearance.. everything.
I didn't remove the spark plugs tho.
the valve were a bit tight so i loosened them to spec.
now I'm Getting some valve Noises even though the bike rides beautifully ( didn't have any engine or idling problems before the adjustment )
noticed some grime on the valve cover ( air filter never changed before ? )
is the link for the sound im hearing
any input is much appreciated :)
 

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brb

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Are you sure its the valves? The clutch baskets make a lot of noise, pull in the clutch if the noise goes away there you go. You may have made mistake that you might want to recheck. It has always been said that 'happy" valves make noise (have clearance), and unhappy don,t (no noise not enough clearance can also have a poorer idle).
 

bigbird

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TDC, 360 degrees when no clearance.. everything.
This phrase you used makes me question you.
So you didn't use the timing g marks on the crank and cam?
That's OK, but at which point was the piston at TDC? On the compression or exhaust stroke, before you rotated the crank another full rotation?
Because one of those 2 possible scenarios would be incorrect.
Not sure why you posted the pictures.
Is that audio clip of your engine running?
Sounds like too much clearance in the valves to me.

Here's my instructions to find exactly what point in the 4 stroke cycle where it is appropriate to check and adjust valve clearance on an NC750
You really don't even need to view the crank and cam position.
Removal of spark plugs is optional but not necessary.

As you rotate the crank counterclockwise, watch the valve train operation.
Your 4 stroke cycle order is Intake-Compression-Power-Exhaust.
Start with cylinder #1 (left side of engine as if you are sitting on the bike)
Slowly rotate the crank counterclockwise.
You are looking for the exhausts (bottom 2 valves) to open and close.
Immediately after the exhausts close, the intakes will open.
As soon as the intakes close, another half turn (180 degrees of rotation) will bring the #1 piston up to TDC (top dead centre).
Stop the crank at that point and with your fingers, try to wiggle the intake and exhaust rocker arms up and down.
You should feel free play in the rocker arms and hear light tapping.
That means it is safe to measure the clearances and adjust as necessary.
The same applies to cylinder # 2.
Start by rotating the crank again and watching the valve action of cylinder #2.

If you did this all correctly already, then you are using incorrect clearances or incorrect feeler gauges.
 
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TheIronWarrior

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You are looking for the exhausts (bottom 2 valves) to open and close.
Immediately after the exhausts close, the intakes will open.
As soon as the intakes close, another half turn (180 degrees of rotation) will bring the #1 piston up to TDC (top dead centre).

Be careful with this one though, the intake valves close 27 degrees after bottom-dead-centre, so another 180 degrees puts you 27 degrees after top-dead-centre.
There is also about 45 degrees of overlap with the intake opening 20/25 degrees before and the exhaust closing 15/20 degrees after TDC (cylinder 1 and 2 respectively)
Always recommended to use the timing marks, though it's likely clearances within several degrees (like +/- 90 or more) of TDC at compression/power stroke are all the same.

If you did this all correctly already, then you are using incorrect clearances or incorrect feeler gauges.
To add to this, feeler gauges are easy to "misread" in the sense that you have to get a feel for the right amount of drag on the gauge. If you don't feel ANY drag, you likely exceed the measurement. If you feel "too much" drag, you're too tight. It's very much a "feel" thing, and people tend to think they don't want any drag, leading to undermeasuring the gap.
 

bigbird

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Be careful with this one though, the intake valves close 27 degrees after bottom-dead-centre, so another 180 degrees puts you 27 degrees after top-dead-centre.
There is also about 45 degrees of overlap with the intake opening 20/25 degrees before and the exhaust closing 15/20 degrees after TDC (cylinder 1 and 2 respectively)
Always recommended to use the timing marks, though it's likely clearances within several degrees (like +/- 90 or more) of TDC at compression/power stroke are all the same.
If one is concerned about valve overlap, then just pull the plugs and use a small rod or coat hanger to determine TDC on the compression stroke.
That's still much easier than trying to pull the cam inspection plug to check cam marks, especially if one has engine guards mounted.
My understanding of the power sports trade is that if a tech wastes their paid time checking timing marks on a valve inspection, they are quickly told by the shop foreman or lead tech to use the shortcut of just watching the valve action and then wiggling the rockers.
Even taking into account valve overlap, it's really hard to screw it up.
Direct action shim under bucket is a more daunting task to determine TDC with their narrower tolerances and not so obvious clicking when unloaded.
 
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670cc

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If one is concerned about valve overlap, then just pull the plugs and use a small rod or coat hanger to determine TDC on the compression stroke.
That's still much easier than trying to pull the cam inspection plug to check cam marks, especially if one has engine guards mounted.
I‘d find it much easier to just remove the cap on the engine cover and use the crankshaft timing mark than to pull the spark plugs out and stick something in the cylinders. On the other hand, the camshaft timing mark serves little purpose as it is easy to determine which TDC is up by observing the valves. I do not mess with the cam inspection plug.
 

TheIronWarrior

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I‘d find it much easier to just remove the cap on the engine cover and use the crankshaft timing mark than to pull the spark plugs out and stick something in the cylinders. On the other hand, the camshaft timing mark serves little purpose as it is easy to determine which TDC is up by observing the valves. I do not mess with the cam inspection plug.
I agree with using the crank mark. Why would pulling one plug per cylinder to shove a stick down be preferred to pulling a single cap for a timing mark? That's twice the removals for a twin, and 4x for an inline 4, not to mention the (small but present) potential for mixing up plug wires (firing order) on some configurations.
I also agree that just watching the valves (you have the cover off already) is going tell you which TDC you're at. The benefit of the cam mark is it also double checks timing (both marks should line up at the same time) but unless you suspect a timing issue, this is likely not needed.
 
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