firatc

valve clearence adjustment

44 posts in this topic

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

 

 

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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.

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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

 

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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. 

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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:

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Posted (edited)

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

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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.

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Thanks Hati.

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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.

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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

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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.👍

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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.

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Posted (edited)

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
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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?

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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.

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

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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.

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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:

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