Valves out of clearance - should I be worried folks?

Sid. Why!? :hehe:

The answer to your question is probably “no - no real need to worry”. I should hope I know, given that my other half is an engine and exhaust expert and we re-shimmed my track bike about a month ago. My track bike is also a twin - it’s an SV650, which is carby with the fuel injected cams on top (hence the need to re-shim, nothing to do with trying to sort any problems out with it - the thing is indestructable - its previous owner must have dropped it more times than Ive had hot dinners…).

Bike engines (as with most engines), so I am told, are an art as much as a science. It might be that your bike LIKES being a little bit astray from the manual. Of course you should always look after it and curiosity is cool too.

The conflict in this thread is the kind of reason why I have said to Mark that we don’t want to do engine work on top of the exhaust work we do. Mark is a genius and he knows his stuff but engines can be made to be incredibly fiddly, when they really dont need to be. There is also a significant different between a race prepped R6 and my piddly 70bhp SV650. So many people have so many opinions on risk and tolerance and what is and is not right in an engine, that it gets really hard to do the right thing (like the number of tablets to take a day on the back of your nurofen packet, the clearances are conservative). And what’s right for one rider isnt right for another! Go figure! Engine work takes an INCREDIBLY LONG TIME to do and it’s REALLY not profitable. For the extra 0.5bhp and fuelling and shimming that we did, which took us a good 8 hours to get right on the dyno, I would rather have built another 2 exhausts and earnt some decent money!

Frankly, Sid, WHY!?!?!?! :slight_smile:

Laughin my t1ts off :DBut like Steve said 25% is a great deal in a high revving engine and the damage wont be immedeate. Not trying to scare you ST. I should have made it clearer. If left the wear on the shims will progress, the slack gets greater and you are more liable to excessive wear. Worse case scenario valves damaged so badly they stick open and the piston hits it. But only if left and never corrected. With what you have at the moment you are not facing imminant implosion of the engine.:stuck_out_tongue: But it is designed to operate within the tollerances specified you can only keep the engine running as sweet as that. Why let it work harder than it should??Point of interest: In a Chinnock helicopter there are 9 gear boxes between the front and back rotors, 0.5mm play in each of those boxes has the potential to multiply up to a 10’+ movement at end of blade of the rotor.

We are all in agreement that the tight shims need to be replaced. My point was that all the talk of burned valved/guides is a bit premature and the evidence presented suggests the engine is in rude health and no cause for any worry of any kind:)

Ah but can I get one in my SV frame!? Mebbe I would take off a little faster!? IMAGINE THE WHEELIES!!! :slight_smile:

Not premature, that’s why it’s clled preventative maintenance . . . we could always leave it till it goes wrong then fix it :Whistling: :stuck_out_tongue:

Put your glasses on Steve;)I’m saying its early to start speculating about engine damage and scaring the bloke into lifting the head.:wink:

The conflict is simply that Chunky likes to argue that black is white sometimes, I think it amuses him :smiley: Hence he reduces it to flymo engines which I think he has a secret longing for.

The work required is simple preventative maintenance, nothing special, service work.

If you’ve ever seen a new set of carrillo rods then you might agree that they look a lot better than some of the supposed art that’s around these days :wink:

I think youre just as bad - just cause it says a set of figures in Haynes doesnt mean it MUST ABSOLUTELY HAVE to be between them. It’s not black OR white. It’s very very GREY - and that’s my point…

Now stop taking shots at each other please and kiss and make up IN PRIVATE. We DO NOT want to see that bit. Just confirm youve done it and we will be happy :slight_smile:

Much love,

Agony Gabs xxx

Yes it does amuse me when theory meets practice.

The question was “Should I be worried?” I am simply answering the question with my practical experience of rebuilding engines.

By you suggesting he inspect the valve seats etc entails hours of work for no practical gain as the clearances are so minutely out of tolerance.

As I said several times, I agree the shims should be changed but there is no cause for concern from the evidence presented on this thread.

I’m getting bored now:cool:

stern voice

Chunkyyyy…

What’s the saying…

“Age and experience beats youthful exuberance”

And Chunks is an ODB

Old Dirty Barsteward :smiley:

I really enjoyed reading your post powerpuffgirl (and the Chunky/Steve debate was informative) - I understand what you are saying - and it obviously comes from experience and knowledge. The main reason I am getting a bit anal regarding the valves is that I bought the kawasaki zx7r with hardly any bills (apart from the first two crucial break in oil and filter changes). I had no bills for clearances - the bike should have had two checks by this time.I’m not a professional engineer - so I defer to those of you who are - but I assume that valve checks are part of the service schedule for a REASON - all authoritative articles on what happens when a valve decides to go southwards/northwards do not make pleasant reading!You HAVE to have SOME set of parameters to stay within for things like clearances, and I agree - they can differ depending on your engines state of tune/what charachteristics you want to get out of it etc - but seeing as I don’t have access to Kawasakis engine testing facilities I think i’ll follow the advice of the Kawasaki engineers who designed and tested the engine and wrote the service manual rather than make up my own rules!:PI also know that a lot of bikers (particularly sportsbike owners) do low mileages and chop their bikes in for the latest model after only a few thousand miles (I have read in your posts that you want to keep the mileage of your ZX10R down) - so these kind of issues are not on the top of their priority lists - I, on the other hand, like to get serious miles out of my bikes - the kind of mileages where regular/irregular valve checks are potentially going to translate into engine longevity/premature wear. So I might as well take the sensible option and follow the manual!:wink:

All fair points, Sid and I think you’re taking a very sensible approach :slight_smile: A happy medium between what all of us are saying :wink:

I just want to clarify that the reason I want to keep the mileage down on the ten is not because I don’t think it can handle a high mileage but because it’s young (07), so am I (28) and I do quite a lot of miles (60 odd a weekday, about 100-200 at weekends). Im quite happy running it to 100k - especially with the backing and resources I have, should I need them (she has been a beauty so far). But she’s a year old and done 11,000 miles. I do an average of 25,000 miles a year and I really really love my ZX10 and want to keep it for a very long time. If I used it every day, then I wouldnt see it in the same light and in about 4 years, Id have hit my 100k! I do a high mileage on the SV instead (which I have a lot of spare parts for because that is one of the bikes I specialise in at work). And the reason Im not using the ten at this precise moment is because I had to use it over the winter for a bit when the SV was only running on one cylinder and it picked up some corrosion following the salt on the road and my failure to clean it enough. I now want to spend the time on it and it is only used occasionally by my other half.

Hope Ive not bored you too much :wink: x

Although valves should be checked as part of services, they often are not as demonstrated by the number of dealers who do not have shims and replacement seals to hand.

I think you need to read the posts again, all I said was 25% too small is too small, no strick adherence to numbers. If Kwak say it has to be between two numbers and it’s measured as being 25% below the smallest number, whatever those numbers might mean, then common sense tells you it probably needs adjusting ;)You can leave your bike badly adjusted if you like but when somebody comes on to the forum and asks a perfectly reasonable question that affects the short-medium term reliability of his bike and gets a crap answer somebody needs to correct it. If I said you can run your brake pads down to the metal I’d expect somebody to correct that.

I understand what you are saying - not boring - always interested to hear other riders experience/perspective on things. You don’t want to pile mundane sh1t like going to work onto the ZX10R when the SV is more suited to that type of thing.

Personally I have held onto bikes over the years rather than part-ex them so that I can use them for specific purposes - e.g. my 98 Hornet is coming up to 50k, has been down the road (scratched etc) and is used mainly in the worst, saltiest winter months (I still cover it in ACF-50 though). Also when I’m out on the p1ss and park up in dodgy places to crash at someone’s flat - i can stick my old hornet outside and it’s probably not gonna attract unwelcome attention overnight. My SVthou is used for the bulk of my commuting. I don’t give a toss about the cosmetic apperance of the bikes - all are covered in a tasteful patina of dirt, scratches, gaffer tape and road grime (I think it gives them charachter) - on the other hand the mechanicals are all pristine - oil, filters, chain and sprockets etc are all carefully attended to - I like the contradiction in this - (a kind of perverse yin and yang philosophical dichotomy that I won’t go into!)

I bought the ZX7R because I’ve always loved them - the reason I’m concerned about the bike is that it has obviously been owned by some lazy git (filthy airbox & filter, ancient calcified plugs etc) - and until I have checked everything out and brought this bike up to my standards I can’t relax!:wink:

Steve. Chill. This is not about you. Its about Sid’s bike.

Did I ever post that bit about using a compression gauge?

Just a plug spanner, a gauge and a squirty oil can of SAE 120 can be a great diagnostic guide.

If all cylinders are about equal and in tollerance after all of the checks, stuff lifting the heads, everything in the valve seat and piston ring/bore wear are about right.

Back to you original question about valve clearances.

Many years ago for a brief bit of my life, I used to rip down Coventry Climax engines. (You may have to google that if you under 50) In their day, these were the small dogs borrocks of single and later twin cam engines.

The mantra was “Never too tight” on the clearances. Sloppy was o.k. The best performing one I ever ripped apart was as sloppy as hell but still went like stink after hours of hard car racing use. Now remember, these things revd like hell. Some got taken to 10K RPM. And never too tight was the mantra.

I’d get the clearances back in tollerance if it was mine and I intended to own it for any length of time. But what do I know?

If you want to give incorrect advice then you need to expect somebody to correct it Chunky, not sure what you’re playing at but it’s not good.I suggested looking at valve seats because he said the head was off, in fact it was the cam cover that was off so obviously not worth taking the head off when there’s no obvious problem.You didn’t originally agree the shims were worth changing, you even said it was only one thou :ermm:

Ok Steve, just for you:

Mark (Mr Engine Expert, does engine work for a living…):

"Sid - seriously the clearances are really not out of spec that much and the Haynes figures need to be cross referenced with the Kawasaki manual as they seem a bit large.

Did you measure the clearances off the bdc of the lobe or did you measure them with the cylinder on compression, because depending on which method you use, you can get another 0.02mm difference."