Valve clearances too loose/tight.

[matt28 401]

24 minutes ago, SteveThackery said:

 

Could you tell us how loose and tight they were?  And exactly how you checked them?  This is interesting.

I was using standard Yato feeler gauges.

According to service manual engine temperature should be below 35*C.

Followed steps from service manual, cylinder 1 as first. 

Valve no.1 out was 0.17 instead of 0.28, in 0.20 instead of 0.18.

Other valves - clerance was about 0.02 - 0.03 smaller or bigger then nominal.

 

Changed coolant as well, for Honda Coolant Type 2.

[matt28 401]

[CFB 4,601]

If I have worked this out correctly from your gaps, it sounds like the engine wasn't quite at TDC.

The exhaust valve hasn't quite come off the cam, thus the inlet valve is not quite on the cam yet.

 

[SteveThackery 3,090]

6 hours ago, matt28 said:

I was using standard Yato feeler gauges.

According to service manual engine temperature should be below 35*C.

Followed steps from service manual, cylinder 1 as first. 

Valve no.1 out was 0.17 instead of 0.28, in 0.20 instead of 0.18.

Other valves - clerance was about 0.02 - 0.03 smaller or bigger then nominal.

 

Changed coolant as well, for Honda Coolant Type 2.

 

Thanks, Matt, very interesting.

That first one - 0.17 instead of 0.28 - was a bus ride away.  Bit of a concern, to be honest.  Makes me wonder if I ought to check mine (even though I'm nowhere near the recommended mileage).

 

I find it really hard to understand how that first clearance could be so far out, unless it was done wrongly in the factory.  And I can't believe that would happen.  Interesting mystery!

Edited July 16, 2017 by SteveThackery

[SteveThackery 3,090]

5 hours ago, CFB said:

If I have worked this out correctly from your gaps, it sounds like the engine wasn't quite at TDC.

The exhaust valve hasn't quite come off the cam, thus the inlet valve is not quite on the cam yet.

 

 

I don't understand this.  You want them both off the cam, don't you?

Anyway, as you approach TDC on the compression stroke (which is pretty close to where you would check the clearances) the last valve "on the cam" is the inlet valve.

Or have I misunderstood what you were saying?  (Most likely, I know.   )

[Tex 36,817]

Correct, Steve. You check them after the inlet has closed and before the exhaust starts to open. This is sometimes referred to as 'on the rock' as the piston goes over tic the valves 'rock' one (or two, obviously) closing and the other(s) opening.

[Guest machinman]

25000, never checked mine💣

[CFB 4,601]

2 hours ago, Tex said:

Correct, Steve. You check them after the inlet has closed and before the exhaust starts to open. This is sometimes referred to as 'on the rock' as the piston goes over tic the valves 'rock' one (or two, obviously) closing and the other(s) opening.

 

Thats what I was trying to say Tex, but got myself in a muddle.

I still think that the cam wasn't quite in the right spot.

 

 

[SteveThackery 3,090]

4 hours ago, Tex said:

Correct, Steve. You check them after the inlet has closed and before the exhaust starts to open. This is sometimes referred to as 'on the rock' as the piston goes over tic the valves 'rock' one (or two, obviously) closing and the other(s) opening.

 

To be honest, though, with an overhead cam I've always just checked the clearance when the rocker (or follower) is on the base circle: i.e. when the lobe is pointed directly away from the rocker/follower.  It just seems easier than worrying about lining up markings, which can be error prone.

 

Is that wrong, do you think?  Does anybody know of an engine which specifies the clearances anywhere other than the base circle (i.e. part way up the quietening ramp)?

[embee 7,288]

I agree with Steve. I always tend to do it one crank rev away from full valve lift (180deg on the cam). It's usually pretty easy to judge the full lift point by eye, give or take a few degrees. Base circle run-out is usually negligible so anywhere reliably away from the ramps should be fine. If in doubt do it in accordance with the manual.

 

Valve timings are usually stated at a certain lift (1mm or something) which is after the ramps, but clearances are always (to my knowledge) quoted with the follower on the base circle. You sometimes have to be careful with finger follower arrangements whether the clearance is quoted at the cam/follower or at the follower/valve.

[SteveThackery 3,090]

35 minutes ago, embee said:

You sometimes have to be careful with finger follower arrangements whether the clearance is quoted at the cam/follower or at the follower/valve.

 

And with a traditional rocker arm, presumably, when it has something other than a 1:1 ratio.

[Graham NZ 1,186]

On 6/16/2017 at 01:48, Tex said:

Anyone who says different is on thin ice..

 

Tex, you have a way with words which often gives me a good laugh.  Thanks heaps!

[Tex 36,817]

Several (most?) of the big Jap fours have you check the clearance with the lobes 'angled'. This means you only have to turn the engine over twice. From memory (and don't shoot me if I remember this wrong, it's years since I did this for a living..) T1 you check half the valves (all on no1, the inlets on 2, the exhausts on 4) and on T2 you check the remainder. The results are always the same as checking with the lobes at 180deg to the valve, btw, but it saves a lot of winding!  

[SteveThackery 3,090]

1 hour ago, Tex said:

Several (most?) of the big Jap fours have you check the clearance with the lobes 'angled'. This means you only have to turn the engine over twice. From memory (and don't shoot me if I remember this wrong, it's years since I did this for a living..) T1 you check half the valves (all on no1, the inlets on 2, the exhausts on 4) and on T2 you check the remainder. The results are always the same as checking with the lobes at 180deg to the valve, btw, but it saves a lot of winding!  

 

I'm sure that's right.  I'm also sure that they will still be on the base circle even though the lobes aren't directly opposite the follower/finger/rocker/etc.

[Tex 36,817]

1 hour ago, SteveThackery said:

 

I'm sure that's right.  I'm also sure that they will still be on the base circle even though the lobes aren't directly opposite the follower/finger/rocker/etc.

 

Oh yeah, it just saves turning the engine numerous times. Some engines (thank you, Mr Designer!) have a plug you remove to put a socket on the end of the crank. Others (you sods!) require you to take an engine cover off.  Those get turned over in top gear (with the plugs out) by the back wheel. Can you spell 'tedious'?  

[Graham NZ 1,186]

Fortunately one of my two bikes has hydraulic tappets. 

[SteveThackery 3,090]

2 hours ago, Graham NZ said:

Fortunately one of my two bikes has hydraulic tappets. 

 

My Royal Enfield has hydraulic tappets, but you wouldn't believe the din they make!  They are noisier than the solid lifters we had previously.

 

Only RE could make hydraulic tappets behave like that, I reckon.

[embee 7,288]

If they are the traditional pushrod type hydraulic "lifters", it's worth taking them out sometime (if that's practical due to the way it's assembled) and depressing the check valve with a thin piece of wire down the hole, and pumping them a few times to flush the working chamber. It can be a little bit of an art to do this, you need to hold the valve depressed while pushing the plunger up/down. They're usually a ball valve, sometimes a flat disc valve, and it's quite possible to get debris under the seat. Ideally this is done immersed in something like white spirit so it flushes the oil out effectively. Don't worry about emptying all the white spirit out afterwards, it'll sort itself out. At a certain car company in Crewe the followers were stored immersed in trays of white spirit before assembly to minimise the chances of dirt entering them.

Alternatively you can usually dismantle them for cleaning, but be very careful not to lose any bits and use a bath of white spirit for swilling them clean, don't use any sort of wipe (paper/cloth etc).

The other thing is the check valves work best with low viscosity oil. The usual problem is with incomplete filling of the working chamber or oil aeration (aeration shouldn't be an issue on the RE). Make sure you use a viscosity as recommended, lower is usually better given a choice.

They are designed to have a small amount of lost motion or compliance, the check valves need some movement of the plunger in order to open and let more oil in, and this avoids pump-up or jacking the in/ex valves off their seats. If the check valve springs have too much load on them the lost motion increases and they can be noisy. The oil filling is by the expansion of the hydraulic plunger which draws oil into the working chamber, they do not rely on engine oil pressure, just a supply of oil into the top chamber.

From Google

 

 

Edited July 18, 2017 by embee

[SteveThackery 3,090]

Thanks, embee.  It's actually a big faf getting to the lifters in the RE.  However, everybody with the later engine (the one with the hydraulic lifters) complains about the din, so it seems to be a generic problem, rather than something specific to mine.  RE say they introduced hydraulic lifters to reduce the maintenance burden, which is fair enough.  And the noise doesn't get any worse.

 

In my experience (which of course is a limited data set), every engine with hydraulic lifters has completely silent valve gear - apart from RE!

 

It's worth mentioning that the engine is air cooled, so it's in inherently fairly noisy anyway.

[outrunner 4,457]

Rather than starting a new thread, I thought I would mention that I had the 16000 miles service done on my 2016 X yesterday and on checking the valves 3 were slack, 1 was a bit tight and the rest were OK. Seems good practice to get them checked as and when required.

 

 

Andy.

[axis 26]

Hi all - I've never checked valve clearances before but am planning to have a go. I've watched the YouTube video and seems do-able. Any advice on what tools etc I should have/get ? I have pretty basic tools, no feeler gauges. thanks

[Dunnster 1,650]

18 minutes ago, axis said:

Hi all - I've never checked valve clearances before but am planning to have a go. I've watched the YouTube video and seems do-able. Any advice on what tools etc I should have/get ? I have pretty basic tools, no feeler gauges. thanks

 

Get some feeler gauges of the right size before you start! 

 

Allow a day as its your first time, it will take you longer being methodical and rechecking everything. 

Work systematically, in a clean tidy way making a note of what goes where, take pictures if needed as you go, you can then refer to them on reassembly. 

I removed the radiator, no big deal as the coolant needed changing, so you will need some new coolant if you do the same. 

If your careful, the rubber valve cover gasket can be re-used. 

Patience, tea and biccies. 

Remove the spark plugs to make TDC easier to find. 

When turning the engine, move it ONLY in the normal direction of rotation (which is the same direction as the wheels turn). If you've turned it too far when lining up the marks, continue turning it counterclockwise until they line up. DONT turn the engine backwards possibility of cam chain tensioner damage. 

Use a ring spanner on the locknuts. 

 

Get some feeler gauges. 

 

[Guest bonekicker]

A fag packet used to be 15 -- but would not recommend it's use any more

[axis 26]

Thanks Mike. Any advise on what type/brand of feelers to get ?

 

[SteveThackery 3,090]

7 hours ago, axis said:

Thanks Mike. Any advise on what type/brand of feelers to get ?

 

 

I'm not Mike, but FWIW I've never found any significant difference between feeler gauges, except in the quality of the enclosure and hinge thing.  Some of the cheaper ones have less legible markings on the feelers, but that's all.