Jump to content

valve clearence adjustment


firatc

Recommended Posts

Spindizzy

Hydraulic tappets modern?  Nah, been in aero engines since WW2 or even earlier. Modern car engines are to some extent going away from them as shims are lighter, easier to produce and pretty much give no problems. Modern engines built to close tolerances and known wear characteristics. Even the Hurley Pugh has hydraulic tappets!

 

Its no indication of modernity. Just appropriate in the right circumstance and design.

 

For info if I had more spare dosh the NC and scooter would gave a HD as a companion. They sound fabulous

 

 

Link to post
  • Replies 63
  • Created
  • Last Reply

Top Posters In This Topic

  • Graham NZ

    17

  • Rocker66

    5

  • embee

    4

Top Posters In This Topic

Popular Posts

Hi, Not disagreeing with what has been said here but I would like to try to clarify some misleading/incorrect descriptions that can be found in various videos, threads and in particular an older

The following may help budding tappet adjusters.   Checking and adjustment is recommended at 12,000km intervals but is that really necessary?  Check out other owners’ findings.   I

The design of the valve cover disappointed me.  No positive means of locating it in place other than the three wavering long screws.  Getting those screws to locate into their threaded holes caused me

Guest Hati
13 hours ago, Graham NZ said:

My Jazz needed a tappet adjustment at 50,000km and then 100,000km.  As the NC engine is based on the Jazz why would it need more frequent adjustments?  Such a low revving engine may need an initial check to pick up any assembly error, but after that it should go forever without adjustment.

 

It is based on the Jazz engine, yes but it is NOT the same engine (or half of). Looking at my service records, half the valves were fine, two were tight and two had bigger clearances. This is at the 24k first valve check on the 750. It was very easy to tell that the engine did like the valve adjustment. It ran noticeably better after the service.

 

11 hours ago, Graham NZ said:

a computer needed to tune it - a lot to maintain and a lot of complexity.

 

There is nothing to tune on the NC except idle. The computer is only needed to read and clear error codes if any. It is actually quite simple from maintenance point of view.

Link to post
embee

Many modern car engines use roller finger followers with hydraulic pedestals, low friction, no maintenance and consistent emission performance, low inertia, high stiffness, and the hydraulic element is essentially stationary (makes life easier for the engineers :) ).

Google image

1-s2.0-S0301679X14003788-gr1.jpg

 

  • Like 2
Link to post
Graham NZ
6 hours ago, aldmannie said:

 

The Harley engine in a Buell Lightning is modern?

 

That's a cracker, best laugh I've had all week.

 

Hey, I never inferred that the HD-based engine in the XB Buell bikes is a modern engine! It is still lovely to use and has a lot of character.  A fair power and torque output too even if less than more modern 1200cc engines.  Yes, it does vibrate, but the rubber mounting system copes well with that once over about 2,500rpm.  3,000rpm is 100km/h.  Here that is our highway speed limit and even from 80km/h the Buell thrums along beautifully in top gear and is a joy to ride.  Below 2,500rpm it is rather grumpy and riding in stop-start traffic is a pain.

 

One of the reasons I added the NC750 to the vehicle fleet is how it produces low-rpm torque and does it smoothly, making it a joy to ride at speeds and in conditions where the Buell is not.  At highway speeds I'd rate both bikes equally pleasant but of course the Buell has a lot more grunt.

 

Some other comparisons are also interesting.  The curb weight of the NC750SD is about 12kg more than the Buell. Ridden carefully, both bikes have similar fuel consumption!  That amazed me when I first had the Buell because fuel economy was not a reason I bought it.

 

I feel fortunate to have both these bikes. 

  • Like 3
Link to post
14 hours ago, Graham NZ said:

 A friend's V-Strom 650 is now on 125,000km and though checked a couple of times, no adjustment ever needed.

 

My V-Strom got to 96k miles with no valve adjustment BUT it uses shims which are more of a pain to adjust (camshafts out!) but rarely need it. 

 

I did my valves at 20k miles and they were a bit tight.  I've loosened them to the maximum recommended so they now make an obvious clattering noise. When that noise stops,  I know I'll need to do them again... :ahappy:

Link to post
Graham NZ
5 hours ago, Mac750 said:

Honda PC 800 has and a shaft drive and a hydraulic clutch and self cancel indicators and  

Oh never mind :)

 

One of my long time mates had a PC800 and loved it for the 100,00km or more he had it.  I rode it many times and liked it too.  Almost bought one but bought an ST1100 instead.  Like many interesting bikes which dare to be different or innovative, both those bikes were often ridiculed un-fairly.  Come to think of it I've seen the NC bikes ridiculed un-fairly. 

Edited by Graham NZ
language error
Link to post
Graham NZ

Which brings me to a point I'd like advice on, please.  How is the radiator dealt with when accessing the tappets?

Link to post
Guest Hati
7 minutes ago, Graham NZ said:

Which brings me to a point I'd like advice on, please.  How is the radiator dealt with when accessing the tappets?

 

You remove it. Two bolts and hoses. So the coolant change gets done a year early.

Link to post
Graham NZ

Thanks Hati.

Link to post
Grumpy old man
7 hours ago, Hati said:

 

You remove it. Two bolts and hoses. So the coolant change gets done a year early.

Do you have to remove the rad? The workshopmanual just refers to lowering it. Just had mine done,  well about 3000 miles ago, pretty sure they didn't change the coolant, didn't charge for it if they did. I'll be doing my own from now on the warranty runs out next month.

Link to post
Andy m

I would have removed it. I'm sure it can be hinged out of the way on the hoses but would still restrict access. The decision probably rests on if you have it on a bike lift or are laid underneath.

 

Andy

Link to post
Guest Mac750

According to the Honda workshop book it can be done by unbolting it to gain access to the rocker cover fasteners.

Odds are the workshop didnt drain the system, so you have to come back for that one at a later date. £££££

 If DIY you may as well drain and remove to get better access your down and dirty anyway.👍

Link to post
Rocker66
10 hours ago, Graham NZ said:

 

One of my long time mates had a PC800 and loved it for the 100,00km or more he had it.  I rode it many times and liked it too.  Almost bought one but bought an ST1100 instead.  Like many interesting bikes which dare to be different or innovative, both those bikes were often ridiculed un-fairly.  Come to think of it I've seen the NC bikes ridiculed un-fairly. 

I wish they had imported the PC800 here as it would have been ideal for my commute.

Link to post
embee

Removing the rad is simple and makes access much much easier.

 

I drain it simply from the bottom hose, I don't disturb the drain screw in the front of the cylinder block. If you're changing the coolant reasonably regularly the relatively small amount which remains in the block isn't significant, changing 75% of it will be fine. First time you might want to flush it with fresh tap water and make an allowance when adding the new stuff for the possible extra dilution, mix the new stuff at 60/40 instead of 50/50 for example, it's not that critical (assuming you use concentrate). A good idea to use de-ionised water rather than tap water for the mix, really cheap from places like http://www.eurocarparts.com/ecp/p/car-accessories/car-maintenance-accessories/car-battery-maintenance/deionised-water/?553771620&0&cc5_146 (order online to get the discounts and collect in store if convenient)  , a little tap water in the system isn't a real problem providing it isn't horrendously hard in your area.

Edited by embee
  • Like 2
Link to post
Grumpy old man
3 hours ago, embee said:

Removing the rad is simple and makes access much much easier.

 

I drain it simply from the bottom hose, I don't disturb the drain screw in the front of the cylinder block. If you're changing the coolant reasonably regularly the relatively small amount which remains in the block isn't significant, changing 75% of it will be fine. First time you might want to flush it with fresh tap water and make an allowance when adding the new stuff for the possible extra dilution, mix the new stuff at 60/40 instead of 50/50 for example, it's not that critical (assuming you use concentrate). A good idea to use de-ionised water rather than tap water for the mix, really cheap from places like http://www.eurocarparts.com/ecp/p/car-accessories/car-maintenance-accessories/car-battery-maintenance/deionised-water/?553771620&0&cc5_146 (order online to get the discounts and collect in store if convenient)  , a little tap water in the system isn't a real problem providing it isn't horrendously hard in your area.

What antifreeze do you use?

Link to post
embee

Personally I use Toyota Red coolant because I have a Toyota and it saves having more than one can on the shelf. I think 5Lts of concentrate cost me around £25 from the auction site a couple of years ago but it does a full change in all my vehicles/bikes, so good for 3-5yrs of my use. All the engines stay clean inside and never had any issues with leaks or pumps etc so it suits me. For example item 221764134022 on the auction site.

 

Other coolants are available.

  • Like 1
Link to post
Derek_Mac

Make sure to use a Silicate Free Antifreeze, your water pump seals will thank you. :)

Link to post
commuter
On 5/19/2017 at 09:37, Graham NZ said:

On a modern, low revving engine?  Unlikely, especially with a Honda. I have worked on engines for 58 years and have never come across screw and locknut tappets working loose.  A fair few seemed welded tight though!

 

A bit too much clearance might be noisy but a good hot idle is a fair indicator that no clearances are dangerously tight.

 

Frequent checking is just a fraud IMHO.

On a previous bike, I suspected that the clearances were never ever even checked  so I painted little which dots to bridge the mating surfaces. On completion of the full service the dots of paint were unbroken. Nuff said! By the way... tight valve clearances would seem to indicate poor quality valve seats or valve pocketing, neither of which should be possible from a company which has been manufacturing unleaded engines for more than a quarter of a century. Slack valves clearnaces can be heard and normally mean that there is a lubrication problem somewhere in order to create the wear for the increased clearance to occur. Wrong valve clearance is the least of your problems.The reason for the wrong valve clearance is what you need to worry about. Most unlikely on Honda engines.

Keep the fluid and filter qualities high and reliability follows.

  • Like 1
Link to post
Graham NZ

So I'm back into the joys of servicing a water-cooled engine, something I've avoided since my 2007 Triumph 900T.  :cry:  Since then I've had a BMW air-head, a Guzzi V11 Sport, Guzzi Breva V1100 and now a Buell, all air/oil cooled and with very simple valve maintenance needs. The Buell has really spoiled me with maintenance; hydraulic tappets and belt final drive. :ahappy:

 

My mate's PC800 needed it's hydraulic tappets because otherwise getting through all the plastic to access the heads would've been a real mission.  :blink:

Link to post
  • 1 year later...
Graham NZ

I removed the radiator and adjusted the tappets today.  I used to think that changing the rear spark plug on my Buell was a fiddly task but I was wrong.  Compared with  some of the tasks on the Honda the Buell is a breeze.

 

I guess that mostly the Honda work wasn't difficult but it was rather fiddly.  Of note are the clips behind the radiator and relocating the valve cover screws.

 

All inlets were about 0.10mm.  Should be 0.18mm.  Adjusted to 0.18mm.  Exhausts on cylinder 2 were OK at 0.28mm but a little less on Cylinder 1.  Adjusted to 0.28mm.

 

I doubt if the tappets had been adjusted since leaving the factory.  I'm glad I did it but hope that  I don't need to do it again.  Changing the coolant was straight forward.

  • Like 3
Link to post
Trev

Well done fellow valve checker/adjuster, are the settings for inlet and exhaust the other way round down there in the Southern hemisphere?:whistle:

  • Haha 1
  • Confused 1
Link to post
Graham NZ

The design of the valve cover disappointed me.  No positive means of locating it in place other than the three wavering long screws.  Getting those screws to locate into their threaded holes caused me a lot of grief and in the end I did it by 'seeing' the screws into place, tricky with the top one.  If a sealant was used, by now it would be smeared everywhere. I didn't use sealant but if ever I do the tappets again I'll fit a new sealing ring.  My bike has done only 12,000km.

 

Some optimist showing a video of how he did the job reckoned it took only an hour or so.  It took me three hours on my knees, mind you since flicking religion long ago I'm out of practice.  A bike lift would help a lot.

 

Starting the engine, it sounded no different with the wider inlet clearances.  My hearing can't distinguish between 0.10 and 0.18mm but a feeler gauge knows the difference.

  • Like 3
Link to post
Guest telboy

Have just carried out the valve adjustment and found the following YouTube video very helpful. 

Please note that you need to double check the TDC is correct by looking at the marking on both the camshaft sprocket and the flywheel markings are both in the correct position.

The job is fairly easy and takes about 2.5 hours. You will also need radiator coolant, I used Honda all season anti-freeze coolant type 2 . This is pre-mixed in a 5 L container and is friendly to the water pump. being silicate free.

 

Link to post
Graham NZ

Thanks, Terry.  I had seen that video.

 

If the NC engine is based on the Jazz one, why does the bike call for tappet checks at 12,000km and the car at 50,000km?

 

Has anyone here carried out checks more than once and if so had the clearances changed in 12,000km?

 

For sure, bikes have become more complicated to look after.  My 'old fashioned' Buell has hydraulic tappets, is air/oil cooled and has belt drive so is very easy to live with. It’ll be a couple of years before my Honda is due for another scheduled tappet check and by then I won’t be fit enough to repeat the recent business.  I suspect that the clearances came from the factory like that because our recent 1340cc Jazz, on which the NC engine is based, had tappet checks at 50,000km intervals so why at 12,000km for the bike?  Oh, yes, changing the spark plugs on the NC is a lot easier than on Buell.  One point to the NC.

 

I had intended to quit my Buell but can't bring myself to do it.  Provided I look after the battery it wakes up after lengthy sleeps are roars off enthusiastically.  Ridden on routes where not too many gear changes are required my arthritic joints can cope with about 90 minutes without a recovery stop.

  • Like 1
Link to post
SteveThackery
23 hours ago, Graham NZ said:

 

If the NC engine is based on the Jazz one, why does the bike call for tappet checks at 12,000km and the car at 50,000km?

 

 

To be honest, it kind of isn't.  It is true that the design was done in consultation with the Jazz designers, and a couple of parts are common (the rods, I think, and pistons?).  But the NC designers laid out the engine quite differently.  I think other aspects are similar - I assume (but don't know) that the Jazz also uses siamesed ports, for instance.  Honda's R&D site gives a good account of the engine development.

 

Nevertheless, your question is totally legitimate - how can there possibly be such a big difference in the check interval?  It doesn't make much sense.

  • Like 2
Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...