Valve clatter.

[Magua]

I did my valve clearances the other day before a carb balance, turns out they were a little tight. Things is, there is now a rapping coming from the top end.
Now I've been reading around the issue, too small a clearance and the valves may not fully retract as the metal expands or if they're too loose you may wear something out.

Here's a video of the offending noise. I would imagine there should be some noise coming from the head anyway otherwise you've left too little clearance?
http://www.youtube.com/watch?v=1ouJgkQoWy8

Just thought I'd check with the Kb gurus rather than whipping the rocker cover back off.

[xwhatsit]

Rattly tappets when the engine is cold isn't bad at all, the noise should slowly disappear on a bike like yours though once warmed up (it's normally not noisy up top, your bike).

So they've closed up since we did them last? You set them from a stone-cold engine (i.e. left over night to cool down)? Sure you didn't do something silly like mix fractions of inches with fractions of millimetres? IIRC on a couple of valves access was quite difficult -- had to flex the feeler gauge to get it inbetween the tappet and the valve, just be careful you haven't set it too wide because of that (feeler gauge should have some friction but still slide OK).

[tri boy]

It's too noisy. Do them again. Also check the cam chain, sounds worn also.

[Ixion]

Did it sound that rattley before? Some engines are noisy, but I'd be inclined to take another look. I seldom use feeler gauges, one never seems to be able to get them into place. Tight thumbnail for inlets, loose thumbnail for exhausts. (My thumbnail is finely calibrated, though it is in imperial measure - i have to convert for Jap bikes.) And check by the wiggle wiggle method.

What clearance did you use ?

[bsasuper]

On a old bike that has high k's it almost impossible to get rid of cam/valve tick because the cam profile/rocker is to worn.

[Magua]

0.1mm for inlet, 0.14mm for outlet. Definately noisier than it used to be.

I'll leave it to sit overnight and drag myself out of bed early tomorrow morning to do them again (I didn't leave it overnight last time, I rode to the shops and back(about a kilometer) and then left it a few hours to cool).


It's too noisy. Do them again. Also check the cam chain, sounds worn also.

I shall consult the Haynes and I'll report back tomorrow.

[jonbuoy]

I use wiggle and click test, Smooth wiggle on the inlets - should be able to wiggle side to side but not up and down, exhaust should be able to lift up and down slightly - enough to hear a slight click (with no oil between the top of the valve stem and the rocker arm). Valve tops may have pitted and worn concave meaning the feeler method will allways be too loose as there will be a gap under the guage that the rocker arm fits into. You will probably be able to see which one is making the noise if you do the "click" test.

[Magua]

I adjusted the valve clearances bright and early this morning, only to break one of the screws that holds the rocker cover inside of the rocker cover. :@

Where could I get one of these? Bolt shop is closed being a Sunday and Mitre ten mega is useless. I get the feeling that I'll be waiting for Honda to open up Monday morning.

Also, what's the best method for removing a half broken screw without pushing it further into the rocker cover? :baby:

[The Pastor]

those are specilised bolts, the bolt shop wont be able to help (but i'd check anyways)

either you're looking at a brand new set from honda (if they make them)

or getting them made.

[racerhead]

Also, what's the best method for removing a half broken screw without pushing it further into the rocker cover? :baby:

At what point did the screw break?
If there is still a small bit sticking out try use a pliers if there is enough access to get at it.
If it has broken off flush or below the hole try gently tapping it in the correct direction with a centre punch or small chisel.
And then if all else fails you may need to drill it but Im sure someone else will have a few more ides before going this far.

[xwhatsit]

Oh you're fucked. Call Econohonda or your mate David Silver. I've got a torque wrench now -- borrow it next time :laugh:

No, it wasn't that noisy before.

[howdamnhard]

Let me guess Magua,it's snapped off on the shoulder were it changes from 5mm dia to 9mm dia.If it has remove the rocker cover,can you grip it with small vice grips? If you cannot you may have to drill it and use an easy out(depends how much access/room you have). Always ensure blind fastener holes are free of any oil(fluid) before inserting fastener in them and attemping to tighten fastener as this will result in a hydraulic lock which then normally leads to a snapped fastener.

[Max Preload]

Where could I get one of these? Bolt shop is closed being a Sunday and Mitre ten mega is useless. I get the feeling that I'll be waiting for Honda to open up Monday morning.

They're called shoulder bolts, but you're unlikely to get one like that - most are cap head not hex and they'll probably only be available as oil quenched so will rust. EDL & Steelmasters do them.

At a stretch you can replace it with a normal hex head zinc machine screw with a fibre washer under the bolt head as long as there are 2 or more correct ones holding the rocker cover location wise.

[Magua]

Let me guess Magua,it's snapped off on the shoulder were it changes from 5mm dia to 9mm dia.If it has remove the rocker cover,can you grip it with small vice grips? If you cannot you may have to drill it and use an easy out(depends how much access/room you have). Always ensure blind fastener holes are free of any oil(fluid) before inserting fastener in them and attemping to tighten fastener as this will result in a hydraulic lock which then normally leads to a snapped fastener.

Well, I just snapped another one. How do I make sure that the hole is fluid free?

[Bonez]

PM me your address details. I've got two stepped bolts I can send you.

You can dab a bit lint free cloth or cotton bud in the hole. It'll remove most of the oil. Couple of dabs if need be.
Then do a dry run as it were by screwing the bolt in the hole before you refiit the rocker cover.

[Magua]

Cotton buds, I'll get onto it. I just got another bolt from action wreckers.

[Bonez]

Cotton buds, I'll get onto it. I just got another bolt from action wreckers.The other thing is it may in fact be botteming out. They don't have to be overly tight, just nipped up, as the large rubber washers and rubber gasket do the sealing. Use a small 10mm ring spanner if you where using a ratchet and socket.

[Ixion]

That's another thing. You do still have the rubber washers in there ? and they're not dried out and hardened up to a bit harder than armour plate steel ?

[xwhatsit]

That's another thing. You do still have the rubber washers in there ? and they're not dried out and hardened up to a bit harder than armour plate steel ?
Individual rubber washers on the bolts, or the rubber sealing gasket for the rocker cover?

[Bonez]

Individual rubber washers on the bolts, or the rubber sealing gasket for the rocker cover?Both can go hard. The sealing gasket and washers tend to break/split.

[Magua]

Both seem to be fine. I managed to get the bolts on without breaking them this time! I'll upload a video later of how it sounds now.

Looked at adjusting the cam chain, but I'm not sure if my chain tensioner works. I undo the bolt at idle and it makes a terrible rattling noise, is that how it's meant to sound? I've heard of some people giving the bike a whack with a rubber mallet after undoing the bolt to loosen it up.

[Bonez]

Both seem to be fine. I managed to get the bolts on without breaking them this time! I'll upload a video later of how it sounds now.

Looked at adjusting the cam chain, but I'm not sure if my chain tensioner works. I undo the bolt at idle and it makes a terrible rattling noise, is that how it's meant to sound? I've heard of some people giving the bike a whack with a rubber mallet after undoing the bolt to loosen it up.Should be quiet once the nut is tightened. Be carefull not the over tighten it. At the other end of the adgustment bolt is a plate which holds the two peices of the spring loaded metal tensioner,which the bade is attached to, together.

[Magua]

http://www.youtube.com/watch?v=gc2aIXKkir8

[Magua]

I use wiggle and click test, Smooth wiggle on the inlets - should be able to wiggle side to side but not up and down, exhaust should be able to lift up and down slightly - enough to hear a slight click (with no oil between the top of the valve stem and the rocker arm). Valve tops may have pitted and worn concave meaning the feeler method will allways be too loose as there will be a gap under the guage that the rocker arm fits into. You will probably be able to see which one is making the noise if you do the "click" test.

Wiggle and click for the win. Renegade and I gave it a shot the other day. Increased performance and decreased revs at 100kph.

[xwhatsit]

Wiggle and click for the win. Renegade and I gave it a shot the other day. Increased performance and decreased revs at 100kph.
Decreased revs at 100kph? You mean you're a gear higher? Or is this the automatic transmission CB400A? :innocent:

How's the noise?

[Magua]

Decreased revs at 100kph? You mean you're a gear higher? Or is this the automatic transmission CB400A? :innocent:

How's the noise?

Hondamatic transmission. In top gear, the revs needed to reach 100 are less than they were prior to the wiggle and click adjustments.

Noise seems a lot better. I'll upload a video later.

[xwhatsit]

Hondamatic transmission. In top gear, the revs needed to reach 100 are less than they were prior to the wiggle and click adjustments.

Noise seems a lot better. I'll upload a video later.
Wot, did you change your top gear ratio while you were doing the valves? :sweatdrop

Glad it's sorted. Might try that technique next time I do my valves, I'd rather have loose noisy tappets than tight ones though.

[jonbuoy]

Wot, did you change your top gear ratio while you were doing the valves? :sweatdrop

Glad it's sorted. Might try that technique next time I do my valves, I'd rather have loose noisy tappets than tight ones though.

Just not too loose mate or you'll increase wear by the rocker arm "hitting" the valve top. If its too loose the rocker arm and valve stem would be making contact later at a steeper part of the cam lobe rather than being eased down on the less curvy part of the cam. Thats why it sounds "noisier" when they are loose - metal on metal contact. Glad it made a difference - I got the tip from the SOHC four website - loads of good info on their relevant to anyone building/repairing older engines.

[Magua]

My idle seems to have gone to shit whilst the engine is cold. 1000rpm or under, climbing slooooooowly as the bike warms. Possible relation to clearances? Coincides, but merely coincidence?

[xwhatsit]

Could it be a carb sync thing? These multiple carb/multiple cylinder bikes are confusing. I know multi owners often seem to whinge about needing a carb sync thing after they do their clearances. How long before it comes right?

[Magua]

Takes quite a long time for it to come right. I just did a balance recently so I'd hope that's not the case.

[xwhatsit]

Takes quite a long time for it to come right. I just did a balance recently so I'd hope that's not the case.
Before you did the valve clearances though? Apparently it changes things, well it would if you had to adjust one cylinder's valves more than the other cylinder.

[Magua]

Idle change came after the adjustment. Damnit, I'm not fond of balancing.

[Ixion]

My idle seems to have gone to shit whilst the engine is cold. 1000rpm or under, climbing slooooooowly as the bike warms. Possible relation to clearances? Coincides, but merely coincidence?

Very possibly. Changing the valve clearance also slighty changes the valve timing, which might well affect idle speed. The slow climb bit is probably the clearance closing up again as the engine heats up. That's what you have a choke for

[Magua]

On the way to work about an hour ago, my idle worsened and the bike began to splutter as I tried to rev. It stalled and refused to start. After about five minutes it decided to start again, but experianced similar symptoms. There I left it and caught a lift to work.

I have tomorrow to attempt a diagnosis before work again at 6.

[Ixion]

Out of petrol. Or water in the fuel.

Or, do you have one of those vile, never to be adequately damned monstrosities, a vacumm operated fuel tap? In which case the hos ehas either come away at one end or other, it it has a leak in it. Or you linked a fuel line while working on it.

Or it's that dodgy electrics plug of yours playing up again.

[Magua]

Out of petrol. Or water in the fuel.

Or, do you have one of those vile, never to be adequately damned monstrosities, a vacumm operated fuel tap? In which case the hos ehas either come away at one end or other, it it has a leak in it. Or you linked a fuel line while working on it.

Or it's that dodgy electrics plug of yours playing up again.

$10 says I'm an idiot, and I ran out of fuel.

[The Pastor]

i was going to text you that, but i didnt want to insult your intelligence.