Valve Clearance

Hi I know there has been several threads regarding valve/tappet adjustment but does anybody actually know the clearance dimensions?

Dirtrider said:

Hi I know there has been several threads regarding valve/tappet adjustment but does anybody actually know the clearance dimensions?

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I don't have the book in front of me, but I'm pretty sure it's on the label on the frame. Left side of the bike, near the swingarm where the tire pressures are located.

trey

VALVE CLEARANCE:

IN 0.17 mm (0.007 in)
EX 0.28 mm (0.011 in)

Thanks, FrankQC! Are those hot or cold clearances?

Cold, as always

Many Thanks FrankQC for the information

FrankQC said:

VALVE CLEARANCE:

IN 0.17 mm (0.007 in)
EX 0.28 mm (0.011 in)

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Pretty high clearances for a short valve train. I would have expected .006" and .008". Explains the "ticky" valves.

Beemerphile said:

Pretty high clearances for a short valve train. I would have expected .006" and .008". Explains the "ticky" valves.

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"Tappy is happy" as owners of older Concours' say (we have screw-adjust rockers, too, albeit with tighter clearances).

I'm impressed that the NC has screw adjust instead of shims - another advantage of the low RPM design and another reason I'm looking at this bike with interest.

centex said:

"Tappy is happy" as owners of older Concours' say (we have screw-adjust rockers, too, albeit with tighter clearances).

I'm impressed that the NC has screw adjust instead of shims - another advantage of the low RPM design and another reason I'm looking at this bike with interest.

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That makes two of us, all my bikes have had screw & nut adjusters, I've never messed with the shim adj. valves. I imagine I could do it if required as others have on other bikes. It just seems easier to check/adjust the screw & nut adj. versions, even though you might have to do it more often compared to the shim adj. models.
Tony

Is it possible to adjust the valves without loosing any oil? I adjusted them at 8k with an oil change but think I did it wrong. I want to get back in there without dealing with the oil.

Aside from a tiny amount of oil that may drip off the valve cover upon removal there is no oil loss when checking or adjusting the valves.

dduelin said:

Aside from a tiny amount of oil that may drip off the valve cover upon removal there is no oil loss when checking or adjusting the valves.

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Thanks dduelin!! I've adjusted valves on a car before and didn't loose any oil because they're in the top of the motor. But with the angle of our NCX motor, I wasn't completely sure. Didn't want a instant oil slick in the garage. Thanks!!

Yes and .004-.005" all exhaust and .001-.002" on all intake. Bike ran better after and fuel mileage became allitle better and more consitant during commuting.

I only had one intake valve (first valve, first cylinder) that was in spec. All the others were a little tight. Especially on the exhaust side. However, I'm not sure I did the adjustments the proper way (hence my last post) so I will will do them again soon. They seem a little "ticky-er" than before but performance hasn't changed.

What's the worse thing that can happen from poorly adjusted valves?

Josh H said:

I only had one intake valve (first valve, first cylinder) that was in spec. All the others were a little tight. Especially on the exhaust side. However, I'm not sure I did the adjustments the proper way (hence my last post) so I will will do them again soon. They seem a little "ticky-er" than before but performance hasn't changed.

What's the worse thing that can happen from poorly adjusted valves?

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The WORST thing that can happen from poorly adjusted valves is leaving them set to tight to where they eventually don't fully close, then the exhaust valves and seats tend to burn. Then you will need to pull the head off and do some repair. work.

Greg

Thanks Greg! If anything, the valves are too loose. I'm not 100% sure the cam rod was in the right position for each side. I rotated the crank shaft to the correct position but just checked if the rocker arm was "loose", then adjusted accordingly. I'm sure this is okay, but reading the service manual I noticed there was a window on the valve casing that would show you if the cam was in the right position. Also, my feeler gauge had two different settings on each feeler (ex.: .008 and .011, next was .009 and .012). I assumed there was a gradient to the feeler and it was noting the skinnier and thicker side of the feeler.

Learning is bliss!

Josh H said:

I'm not 100% sure the cam rod was in the right position for each side.

Also, my feeler gauge had two different settings on each feeler (ex.: .008 and .011, next was .009 and .012). I assumed there was a gradient to the feeler and it was noting the skinnier and thicker side of the feeler.

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Ack

The two numbers on each feeler guage should denote the singular uniform thickness, just represented in both metric (mm) and inches.

The "bigger" number, will be the metric measurement, the "smaller" one, the decimal inch ie: [.008] would be 8 thousands of an inch, and the mm equivalent *should* be [.2032] (rounded off, it's considered [0.20] usually)

I used a "Go-No-Go" type feeler...whatever that means...


Ah! Just read about the Go-No Go feeler gauge in another forum. I'll definitely have to get back in and make sure everything is right. Probably should have done my research beforehand....

Josh H said:

I used a "Go-No-Go" type feeler...whatever that means...

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Augh, I feel old

I've never seen or heard of such a thing!

Apparently, it means exactly what you had said, about them being thinner and then thicker.

Huh. Who'd a thunk.

Take my previous post with an eye towards the conversions of decimal inches to mm being still valid, but with care about not mixing the inappropriate thinner-thicker listings with each other, as far as that goes.

Is there less work in checking the clearance with a feeler gauge compared to actually adjusting the clearances? ie do you have to strip more stuff off the bike to make the adjustments?
Mike