Valves - do I really need to check them?

[Newoldbiker 45]

Having decided to shun the £500 offer to service my bike and fit new brake pads after 16K miles and having looked up the maintenence schedule the one job that seems a bit technical is the valve check.  Is it really necessary?  My bike starts first time, delivers 75-80 mpg and runs fine.  Is it a case of 'if it's not broken just leave it'?

 

any advice very welcome

[Guest bonekicker]

Is it a case of 'if it's not broken just leave it'?

 

Firstly I am all in favor of DIY--and there is a excellent video of the adjustment of the valves on Youtube--it looks straight forward.

 

I also was told by Preston Honda that they don't do the valve check --unless the engine showed signs of not running correctly--but this was to be shown on the service computer as not--or did need doing???      75-80 mpg sounds like the bike is running just fine to me?? 

 

But the problem is the warranty??  If you don't have it done??

 

But the price for doing the work is stupid to say the least !!!

 

Can you ask the garage to convince you they need doing--or are they just saying they need doing-- without using the service computer that they do need doing??   

 

​Paul --its a endless argument I am afraid--no right or wrong decision-- it's really up to you!!!! 

 

​The bike was advertised as a economical bike bike to maintain --- Is it Really???   

Edited September 4, 2015 by bonekicker

[mcress 139]

I'm at 23k on my 750 and I didn't have them done. Still runs the same as the day I bought it. I will check them next month when I do the 24k service, but not expecting them to be out by much.

[Guest R120]

I had mine done at 18k, now on 23k, and i could tell the difference, bike ran a lot better, though before it was serviced i wouldn't have said it needed doing.

[Newoldbiker 45]

It's out of warranty in November.  I'll see.  Like I said it's running fine - Cheers chaps for your help 

[Guest Lenp]

My 750x is coming up to 2years old,warranty coming to a end,ready for a service 7000 miles on the clock. This is what has been recommended by the Honda Dealer, new air filter,oil,filter,new oil,new brake fluid,new spark plugs ,if required, and a check over,the mechanic, is very good at is job that's why I have gone to Newton Abbott,,,,the price,,well they said its two and a half hours job ,which including taking of the no tank for the plugs and the filter,,,,,,,£260 total ,,,Ride Safe....

[Newoldbiker 45]

Unfortunately Newton Abbot is a bit of a schlepp for me.  Bloody London Prices 

[aquaboy 105]

Don't touch them if its running fine. Its a throw back to the old days when the seats weren't hardened. Remember when leaded fuel was discontinued older vehicles with caste iron heads had to have hardened seats fitted as they eroded away so the valve starts to stay open slightly which is not good.

 

 Aluminium engines have  always had harden seats and as our bikes are designed to burn very lean (and hot) (no deposits) the seats

and valves will be well engineered. I wouldn't expect to touch mine in the life time of the bike.

[aquaboy 105]

Change the oil and filter, if the brake fluid is clear (say like unused chip oil) its fine.

 

Give the air filter a hoover, obviously from the right side to suck the dirt back off and not from

the engine side which would suck the grit deeper into the element!

 

Have a look at the pads, make sure they all have a similar amount of wear and are flat.

Its so easy these days with the internet so even if you don't really know what a set of worn

pads look like just google images of new verses old. Don't forget to put a tiny smidge of copper grease

on the back when you put them in. The area where the pistons push against.

[motorbykcourier 293]

Sorry I DONT agree...

If you really want your engine to last.?? ... and YES it will last reasonably as it is a HONDA after all !!

But you run the risk of burning valves / seats to say the least... regardless of how well engineered the product is.

 

Re air filter - change it sooner rather than later. I'm afraid a vacuum will not remove the crud and debris that really affects the membrain of an air filter

Plugs....

Your fuel consumption will suffer, as well as general engine response and performance

 

Ok I've made a point

a) its based on my experience as an engineer in a former life

experience of running this bike

 

Also, as mentioned in earlier / other post, the 16K mile service has 6 hours by Honda put aside to complete it

I reckon Honda do this for a reason and NOT just to 'fleece' the unwearing....

[fj_stuart 4,753]

Here's my thoughts on the subject. First of all I'll say I don't have an NC (yet!) and currently run a pair of Yamaha FJ1200s and a Honda CBF250. All the bikes have high mileages & I do all my own servicing (pretty much as per the book) The valve check interval on both the FJ & CBF is 8,000 miles which works out at once a year. (I do 16,000 miles per year using one of the FJs & the CBF)

 

older FJ -  134,000 miles 16 valves - 20 shims changed

newer FJ -  92,000 miles 16 valves -   3 shims changed

(I've no idea why the new bikes has needed fewer shim changes)

CBF -          52,000 miles   4 valves - 5 shims changed

 

 

Note that valve clearances only ever get smaller. The wear in the cam, shim & bucket is minimal, the gap closes as the valve bashes itself (very slightly) into the head. If I'd never checked the valves would the bikes be running ok? Probably - each valve has generally had a single shim size changed (0.05mm) so here would still be a gap albeit too small.

 

Should you check the valves? Well you can't wait until the engine starts to rattle because it won't - the gaps will only close up. I would check the valves on my bikes but I am experienced in engines and have the time & a good garage & tools. Think of it this way - would you not check the oil level because your bike is running ok? No, because by the time you noticed it, it would be too late.

 

Sorry for rabbiting on but I hope this helps. 

 

Checking the FJ's valves - pretty good access.

 

[Newoldbiker 45]

On YouTube there's a film that says the bike needs to be stone cold to check the valves - is this true?

[Guest bonekicker]

Yes the garage will always ask you to bring the bike in the night before--to ensure it's stone cold sober 

[Guest Hati]

Not stone cold, I think they talk about 20 C or thereabouts. Basically ambient temperature.

[aquaboy 105]

I did say do the oil and filter!  

 

I think Stuart has made the point for me, Look at the minimal adjustment and the high mileage he has achieved.

 

I think for the vast majority of us on here who will do nowhere near that sort of distance   should leave well alone.

Many non engineers, and I speak as an ex shift maintenance engineer, taking care of a bronze foundry/processor have no idea

in practice how to use feeler gauges and will do more harm than good. Come to think of it there are several young lads working in bike workshops that I wouldn't want anywhere near my bike either.

 

 

And don't get me started on warranties and what a con they are!!

[nelmo 563]

My last bike had 2 valve checks - first time at 65k miles, second at 96k miles. No adjustment needed either time.

However, that bike had shims - the NC has screw adjustors which I'm told are easier to go out of tolerance.

I plan to do a check at 32k miles...

[Newoldbiker 45]

Thanks Neil - how many miles have you done thus far?

[Dunnster 1,650]

Whilst getting new tyres fitted, I asked how much it would cost for the valves to be checked as my NC700x had just passed 16000 miles. 16,001 infact as I stopped outside the garage.

The mechanic said "90 quid."

I said "could you change the coolant at the same time?"

He said "yes, call it £100. To be honest you could leave those Honda engines until 24-30,000 miles, before checking."

Not a Honda garage, just my local independant. I was going to attempt the check myself, do everything else, but for that price, think I'll leave it for the experts. Gonna watch though incase I fancy attempting.

[Guest EasyTiger]

My 750x is coming up to 2years old,warranty coming to a end,ready for a service 7000 miles on the clock. This is what has been recommended by the Honda Dealer, new air filter,oil,filter,new oil,new brake fluid,new spark plugs ,if required, and a check over,the mechanic, is very good at is job that's why I have gone to Newton Abbott,,,,the price,,well they said its two and a half hours job ,which including taking of the no tank for the plugs and the filter,,,,,,,£260 total ,,,Ride Safe....

I'd be astonished if you need expensive new Iridium plugs after 7,000 miles. The Honda schedule doesn't have them renewed until 32,000.

This may be a throwback to the olden days, but modern plugs and systems are much more long-lived - mine showed no signs of wear at 16,000, which is the first time they need inspection.

[embee 7,288]

the stock plugs in the NC are, as said, iridium and will be good for typically a minimum of 50k miles in practice.

[fred_jb 10,265]

I did say do the oil and filter!  

 

I think Stuart has made the point for me, Look at the minimal adjustment and the high mileage he has achieved.

 

I think for the vast majority of us on here who will do nowhere near that sort of distance   should leave well alone.

Many non engineers, and I speak as an ex shift maintenance engineer, taking care of a bronze foundry/processor have no idea

in practice how to use feeler gauges and will do more harm than good. Come to think of it there are several young lads working in bike workshops that I wouldn't want anywhere near my bike either.

 

 

And don't get me started on warranties and what a con they are!!

Don't even know where my feeler gauges are these days.  Probably last used setting plug gaps and valve clearances on the MG Metro engine I had in my Midas kit car!  Maybe also ignition breaker points, though I can't remember - maybe it had a new fangled electronic ignition fitted!

 

Fred

[aquaboy 105]

I worked with someone who bought a brand new Rover 100. (a posh metro) Apart from the oil and filter he never touched it. There was big debates going on at the time about cam belts. He kept on welding up the rear subframe every other mot once it was 5 or 6years old but never did the cam belt. It got to 110,000 miles and 11tears old before it broke. It was so rusty he just scraped it, never had the expense or hassle of doingthe cambelt tho'!

[Tex 36,817]

Interestingly, the cam belt on the Rover 100 had a change interval of 100,000 miles. So they got the projected life about right!

[Tonyj 6,907]

Interestingly, the cam belt on the Rover 100 had a change interval of 100,000 miles. So they got the projected life about right!

It's just the shame of owning said vehicle , they had to make up for it some how.:0)

[Guest SimonR]

I had my NC700X valve clearances checked, after much deliberation about the dealer cost, at the 8k mile service; they were spot on the factory fresh adjustment.

 

So they won't be getting another look until 24k miler at the earliest. Currently on 15k miles, the bike runs more than fine