Valve clearances.

[stupotads]

Can anybody tell me what are the symptons ( if any ) that the valve clearances need checking ? I have been told that the engine may rattle slightly if the clearances are out at all.
When my NTV650 is cold, it always has a slight rattle for the first 5 minutes or so until the oil warms up. Is this normal, or should I consider getting the valves checked.
The engine runs sweet & returns good mpg.
Thanks.

[rj2para (Bisto)]

No idea on the valves but my engine sound like that when it needs a bit more oil.

Not that I ever let it get that low you understand.

[De Graaf van Salland]

I did my valves last winter, but I didn't notice any difference.

But there are 2 youtube video's about the noise. If you listen carefully, you'll hear a difference.:

Before adjustment:


After adjustment:


The video's were uploaded by a "jcsmartins". According to youtube this person lives in Portugal. Is (s)he perhaps known to our Portugese members. Or is it an alias to one of our Portugese members ?


GvS

[smartiedarkblue]

if you get a rattle for the first few minutes that would suggest tappets are out a touch, as after a few minutes they warm up and take up the slack.

they should always be checked with the bike stone dead cold, i.e. after the bike has been stood overnight.

I would recomend checking the rear unit first as this is easy. I warn u the front unit is a pig. i found it easier when doing it to remove:

airbox, carbs, radiator, heat shield, drain water, remove thermostat housing. All this just to check them. If you take to a stealer they will charge a fortune as its about 3 hours work but they will probably charge 5 hours.

Get a haynes manual as this talks u through very easily the gaps are: INLET= 0.15mm EXHAUST = 0.20mm. I would recomend setting inlet valves a touch more at around 0.18mm though.

take it easy
ed

[undercover]

Jul 29, 2011 10:00:03 GMT 1 smartiedarkblue said:

Get a haynes manual as this talks u through very easily the gaps are: INLET= 0.15mm EXHAUST = 0.20mm. I would recomend setting inlet valves a touch more at around 0.18mm though.


hi smartiedarkblue i am going to be doing my valve clearences soon as i have stripped the bike .
but one thing the haynes manual dosent mention is inlet and exhaust valves where are they
not sure is there 1 exhaust valve per cylander and 2 inlet valves please help
also why would 0.18mm be better than 0.15mm
sorry to ask this as valves are new to me

[gills]

Jul 19, 2013 2:48:55 GMT 1 undercover said:

is there 1 exhaust valve per cylander and 2 inlet valves please help
also why would 0.18mm be better than 0.15mm
sorry to ask this as valves are new to me

Yes, 2x inlet/1x exhaust per cylinder. Inlets are in the middle of the V, closest to the carbs.

The gaps close up as the engine warms, so a slightly larger gap gives more room for error if the engine gets v hot. Also, gaps will close up over time as the valve seats wear and the valve moves up in the head, closer to the rocker assembly (this is why the gaps need adjusting periodically). Inlet valves get more cooling from incoming air, so expand less and so need a smaller gap. Exhausts valves run hotter and need a bigger gap. If the gap closes up entirely, then the valve doesn't seat properly when closed and you start to get gases escaping during combustion - very bad news!

[rob]

Confession time. My engine is just approaching its 43000 mile birthday and I have never, ever done the valves. Everything else service-wise with religious devotion but dismantling half the bike to find no action is required has proved to be a soul destroying prospect in all this time. They don't rattle and, given new plugs, oil and filters regularly, performance and mpg don't seem to be any worse now than when the bike was new.

I expect the person who engineered this little nightmare into the life of NTV owners has long since done the decent thing and devoted the rest of his life to charitable works. My CX500 and R80 got valve love all the time but the NTV? Never had the rocker covers off.

I was searching the boards for reassurance that there's an easier way than Haynes's but it looks like not. If I do get a renewed sense of diligence in the valve clearance dept, do I REALLY need to drain the cooland system and remove the rad and thermostat housing or can I get away with just pivoting the radiator out of the way? Any help/advice/straight talk reluctantly received. Unless you are that particular designer who caused the problem in the first place, in which case I'll expect you round here with your spanners and feeler gauge.

[gills]

I think you can do it by unbolting, but not removing, the thermostat cover and radiator. Having said that, actually draining and refilling the coolant is a very easy job once you're already taking it to pieces.

If you wanted to see if valve adjustment is likely to be needed, why not just remove the rear rocker cover and check those? It's much quicker/easier to do than the front!

[rob]

Thanks gills. True, and decoupling the airbox looks easy stuff too. I thought that approach would only tell me half the story but I suppose it would give a good indication at least. I'll give it a go and cross my fingers for a snug fitting feeler gauge - if I can remember where I put it. All the best.

[undercover]

Jul 29, 2014 0:39:14 GMT 1 rob said:

Confession time. My engine is just approaching its 43000 mile birthday and I have never, ever done the valves.

i had a little oil leak at the front rocker cover last year and the valve clearances checked by a mechanic he told me the valves settings were all good and my bike had 42000 miles on the clock.

but only he never replaced the gaskets only cleaned them up and sealed them up
so i notice my idle was hunting badly when i put the bike back on the road this year
and then noticed the front rocker cover weeping oil again.
so i stripped the bike down radiator off valve covers off didn't even bother checking the clearance's
just cleaned up the rocker cover put some vaseline on the new gasket and tightened them down 10nm

cleaned the carbs and now the bike is running very nice.

i wouldn't worry about the valve clearance's

but why does every bike i have had the rocker cover gasket start's leaking around 45000 miles
i have a suzuki gsx750f and low and behold i just bought it a new gasket.
  
   

[rob]

Thanks undercover, you can tell that I'm not panicking about them either. Maybe rocker covers leak because the material shrinks and hardens a bit. My old, long in the tooth CX500 would weep at the rocker gasket - probably less than a quarter of a teaspoon between oil changes though. The rocker bolts on that screwed down to a fixed stop so the seal itself was only ever compressed a certain amount. Overtightening it to improve the seal just ended up in a stripped thread in the casing (and then it REALLY leaked). Funnily enough, most of the valves on the CX needed some tappet adjustment whenever it fell due, which encouraged me to do it regularly, which meant disturbing the rocker cover and seal every 6 months... and so on.

[undercover]

i have never had a cx500 but my ntv 650 has been hard enough work since i got it.
but now i only need to sort out the fan that dose not work but don't need to worry about that in the uk really.
i did solve the fuel tap problem that was the dirt in the top of the brass pipe
now my reserve works

i worked out the fuel goes down the brass tube and reserve must go down the outer
kind of weird that the dirt that collected at the rubber middle bit of the filter
stopped the fuel from going into reserve.
but i suppose there is a fuel pump

after being stranded out in the pitch dark on a country road at 10 o'clock
at night with a full reserve tank full of petrol thinking i had ran out.
flattened the battery and told the rac who came to pick me up
the bike just splutterd and died.

funny thing is went out on bike with a spare gerry can of fuel to test reserve was working
out in a country road
bike splutter and runs out of fuel.
i pull the bike off the road a van pulls up 1 min later and ask's do i need petrol he offerd to go and get some for me.
i explained and told him turned the reserve on waited 2 mins and off i went.
never happens when you need it most
but glad that's fixed.

[rob]

I have a feeling my NTV, after 14 years off the road, has a fan issue as well - something to sort out over the winter maybe. I never remember it coming on even when I was using the bike on a daily commute or touring. Just need to keep an eye on the gauge and stop if it creeps too close to the red.

[undercover]

Hi rob

i have opened my fan motor to see if it is serviceable it is but it is quite impossible  to reassemble as there is tiny springs that push what i can only describe as pencil led onto the motor.

and even drilling a hole in the plastic fan cover      ''thinking i could use a rubber plug to seal it later''.
so i could hold everything on both sides in place
when i got everything as should the spring seized in its fitting and the other one popped out and flew across the room.

i quickly put everything in a bag and washed my hands.

i will take pictures to show everyone the working of the fan and how it would be fixable
the problem is that putting it back together is impossible.

however i measured the bracket that holds the fan and recess that holds the motor and fan is 7 inches wide the full fan bracket is bigger but
obviously i am looking for something to fit in the fan bracket that is 7 inch wide

  www.ebay.co.uk/itm/201079408124?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


looks good and a lot cheaper than oem honda part even though the ntv650 fan has now been discontinued anyway.

don't be tempted to buy someones old rubbish on ebay my bike is a 97 model and 42000 miles on the clock.
and the fan and bracket on mine is rotten.

here is another thread that is similar

ntvhonda.proboards.com/thread/4131/radiator-fan-knackered-fans-bikes

[rob]

That's a coincidence, I was just contemplating doing the same today (though planning it for a winter project). The sprung pencil leads are the carbon brushes which carry electricity from the motor's coiled wire to the fan's rotor to turn it. If the rest of the cooling system is working OK, you should be able to happily carry on using the bike as the fan seems more of a last resort and isn't the primary method of cooling the water jacket. I'm 99% sure my problem is the thermostat not opening so the water isn't circulating. Somewhere, possibly on this ntv board, I have seen a procedure for the controlled disassembly of a fan and its motor. Then again, it might have been Youtube. This might have been it: youtu.be/MAvbOGxdxaQ

I've taken other electric motors apart and you need to keep any bearings and shims in order and, if possible, remove the brushes first. Obviously, I'm not intimate with the innards of the NTV's fan motor but they all follow the same basic principles. There is some info here also: ntvhonda.proboards.com/thread/379/cooling-fan-problem-help

Maybe try to find the bits and try again?

I suppose if a new one is out of the question, reconditioning an old one may be the only option - unless there's a current fan/motor assembly that would fit the dimensions?