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firatc

noisy engine after valve clearance adjustment

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firatc

Hi folks, 

 

After adjusting the valve clearances on my NC700, the engine became a lot more noisier and engine response became a lot more smoother. All valves very tight before the adjustment.

I presumed the noise was normal, until, a bike mechanic also picked up on it when he mentioned the engine shouldn't be this loud and asked if I had enough engine oil ( which I do ).

 

I uploaded a video of the sound the bike makes - hopefully you can access the video below fine. 

Does it sound like there is something wrong with it?

I had taken it to Honda service at 16K and had specifically asked for the valve clearances to be adjusted ( Major service ). At that time I never noticed a noise change.  This time I did the service including the valve clearances and here is the result :)

 

NC700 XA-C, 2012, 31K Miles

 

 

 

I hope everyone is keeping well...

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bigbird

I definitely hear a lot of clacking, likely from the valve train.

I assume you did the valve adjustment yourself?

You need to recheck the valve clearances and adjust as necessary.

There are several things that could go wrong, such as not using the correct feeler gauges, forgetting to tighten the locknuts on one or more of the rocker arms, or not having the timing marks properly aligned.

At least too much clearance is better than not enough clearance.

You won't damage anything idling the engine, but don't drive it until you fix the issue.

 

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Trev

Yup too noisy by far, time to recheck what you've done I'm afraid

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Defender

Sounds like an old Simca and that's not good!

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wjvh

Number 1 cylinder is the RIGHT side as you are looking at the radiator; or if you prefer on the LEFT side as you are sitting on the bike. Make sure that you have the timing marks correct and that you are on the correct stroke of the piston when you set the valve clearances; there will

be info on this forum to help you, just search / google as I can’t remember. If all you’ve done is let it tick over like that then you won’t have done any permanent damage. Just read the instructions carefully and take your time, you’ll get it right. 👍 and well done on trusting your instinct that it did not sound right. One other thing - don’t rotate the pistons ‘backwards’ as that can cause the camchain to slip, if you miss the timing mark just move forwards until you get to the right spot. 

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MikeBike
1 hour ago, wjvh said:

Number 1 cylinder is the RIGHT side as you are looking at the radiator; or if you prefer on the LEFT side as you are sitting on the bike. Make sure that you have the timing marks correct and that you are on the correct stroke of the piston when you set the valve clearances; there will

be info on this forum to help you, just search / google as I can’t remember. If all you’ve done is let it tick over like that then you won’t have done any permanent damage. Just read the instructions carefully and take your time, you’ll get it right. 👍 and well done on trusting your instinct that it did not sound right. One other thing - don’t rotate the pistons ‘backwards’ as that can cause the camchain to slip, if you miss the timing mark just move forwards until you get to the right spot. 

I seem to remember that there was an instruction online somewhere (YouTube Vid?)  that had the cylinder numbering the wrong way round.

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SteveThackery

I concur - this is definitely not how it should sound.  I wouldn't ride it until you've got to the bottom of it.

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outrunner

Sounds like a bag of spanners falling down a metal fire escape, best do the valves again.

 

Andy.

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Xactly

Sounds to me like you’ve fixed it until it’s broken...

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davebike

Valve clearence done at thew wrong TDC  by the sound of it  ! 

Simple if noisy mistake

 

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shiggsy

There is an early version of the Workshop manual that has a misprint that tells you to rotate the crankshaft until the cam mark aligns with an upper mark, this is wrong it should align with the lower mark.

 

Cylinder 1 is Clutch lever side, or left side when sitting on the bike.

Cylinder 2 is Brake lever side, or right side when sitting on the bike.

 

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MikeBike
37 minutes ago, shiggsy said:

There is an early version of the Workshop manual that has a misprint that tells you to rotate the crankshaft until the cam mark aligns with an upper mark, this is wrong it should align with the lower mark.

 

Cylinder 1 is Clutch lever side, or left side when sitting on the bike.

Cylinder 2 is Brake lever side, or right side when sitting on the bike.

 

THe 700X PDF version downloaded from a site not dissimilar to this one looks like it has this..

Quote

No.1 Cylinder: Make sure that the "1" mark [1] on the cam sprocket is
aligned with the upper cylinder head index line [2].
No.2 Cylinder:
Make sure that the "2" mark [3] on the cam sprocket is
aligned with the upper cylinder head index line.
If the "1" mark or "2" mark is facing lower cylinder head
index line [4], turn the crankshaft counterclockwise one
full turn (360°) and realign the "1T" mark or "2T" mark
with the index notch.

 

So if he followed this it could be the reason according to @davebike.

 

THe later 2016-2020 manual says for reference (similar for Cyl 2) (Page 3-8):

Quote

No. 1 Cylinder: Rotate the crankshaft counterclockwise and align the
"1T" mark [1] on the flywheel with the index notch [2] on
the alternator cover.
 
Make sure that the "1" mark [3] on the cam sprocket is
aligned with the lower cylinder head index line [4] .
If the "1" mark is facing the upper cylinder head index
line [5]. turn the crankshaft counterclockwise one full
turn (360°) and realign the "1 T" mark with the index
notch.

 

 

Good call!!!

Edited by MikeBike

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bigbird

There's a much easier and in my mind foolproof way to check and adjust valve clearances without worrying about aligning timing marks,

 

Here's my method of inspecting/adjusting valves on any engine without giving a care about cylinder numbers, timing marks, or anything else.

Seasoned mechanics never remove the timing caps and squint through the hole trying to align the marks.

All you need to do is remove the cover of the crankshaft bolt to allow you to easily turn the crank with a ratchet and socket:

As you rotate the crank (counterclockwise only), watch the valve train operation.
Your 4 stroke cycle order is Intake-Compression-Power-Exhaust.

All valves are closed from slightly after the beginning of the compression stroke to almost the end of the power stroke.
Start with any cylinder.
Slowly rotate the crank counterclockwise only.
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 will bring the  piston up to close to TDC (top dead centre).

That's close enough. The piston does not need to be exactly at TDC.
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 all the rocker arms for that cylinder and hear light tapping.
That means it is safe to measure the clearances and adjust as necessary.


On to the next cylinder.
Start by rotating the crank again and watching the valve action of the next cylinder.

 

This saves a huge amount of time and is foolproof as long as you remember the order of the 4 stroke cycle and thus the order that the valves open and close.

Edited by bigbird
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davebike

Yes Bigbird exactly as I was taught as atranee mechanic at Suzuki training corse XX  years ago used it ever since

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