Cylinder Head knackered on a 2000 R6 5EB

[MikeyC]

So my bike hadn't been used for a few weeks. When I went to take it out, it was dead as a dodo. I initially thought it was the battery, so charged it up for a few hours. Still nothing. Bought a new battery, changed it over, still, exactly the same.

Now i'm not technically minded at all, so that's as far as my expertise stretches So I got a mechanic over to check it out. He thought it was spark plugs. So he went to change then, but when he did, he did a compression test. All 4 cylinders showing 90psi, which he said is very low. He then basically said I need a new cylinder head. He explained why but if i'm honest, I can't even remember what else he said

Problem is, I can't get the bike anywhere to get it sorted. Do i spend a few hundred getting it sorted with the worry that, as an old bike, it's only going to cause me more problems? Do I sell the bike as a non-runner? What to do?

[andym]

I believe it should be around 120psi, but it should still run at 90.

[Pete.]

Your bike ran a few weeks ago and now it doesn't start? A knackered cylinder head is not the cause of that and as AndyM says it should still start and run. Low compression could be valves or pistons/rings but your main problem is it's not starting.

Try giving us a better description of the symptoms than 'dead as a Dodo' because that suggests that you get absolutely nothing from the bike even electrically. If it were true you couldn't crank the engine to do a compression test.

What does and does not happen?
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[MikeyC]

Yeah fair point Electrics work - The kill switch is switched off and I then attempt to start her up, I can hear it attempt to start for literally a second, and then nothing. Silence.

Best way I can describe it I guess, is when you try and start a bike and its just cranking over and over but never creates that spark and actually starts? Its that crank noise but I get it once and then nothing.

Does that make sense?!

[Pete.]

Ok, so you have electrics, the bike cranks over but doesn't fire and it only cranks for a second then stops. You've fitted a new battery and it still does the same?
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[MikeyC]

[Pete.]

Well no wonder your compression figures are low. To do a compression test you need to spin the engine up on the starter with the throttle held open. If it's only turning briefly you will always get a low figure.

Sounds like the mechanic has seen the chance of a cheap bike by making you believe it's a lot more knackered than it is.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[MikeyC]

I wasn't there when the mechanic was working on the bike - he came as a recommendation, so would like to think he wouldn't be like that... plus he didn't tell me he can fix it and didn't charge me anything, as he couldn't fix it. But... who knows!

Problem I have now is, how do I get the bike up and running with not being able to get it anywhere? I don't want to be spending hundreds and hundreds of pounds on a bike that's only worth £1500 either....

[jaffa90]

The engine should turn over briskly when pressing the starter button.
Have you good battery connections to the bike?

[andym]

A problem I used to have (quite rare now), was every now and then the engine would turn over then just lock up (sometimes with a thump, other times just stop dead), if I pressed the start button the starter would just click, a few rapid presses of the start button would sort it out though.

Also, (and I know there are a lot of people here who will say not to do this), if you know someone who has a car and jump leads, use them to try jumping the bike.

[Nobby the Bastard]

[andym]

[BusterGonads]

[Pete.]

The thing is, unless the OP's been playing silly buggers and bouncing it off the limiter bending valves etc there's no reason to believe that the non-starting is simply the fault of low compression. It causes lack of power, poor difficult starting, unsteady idle, smoking exhaust etc but it doesn't suddenly turn a bike that starts and runs one week into one that no longer start the next. It's a gradual degradation.

Year 2000 bike is still carbs. OP says it spends long periods standing. Carbs need a strip and service IMO. Failing to crank over is another issue.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[stevo as b4]

I once knew of a nutter with an early R6 who always thrashed it and always kept up with his mates on Fireblades, ZX9R's, and GSXR 1000's etc.

I remember him saying something about getting another head, as you get valve seat recession in under 20'000miles from hammering the arse out it it. I didn't think much of it other than that the guy sounded like a nutter, but maybe he was onto something. Yamaha might not have tested 10'000miles of 13000rpm?

[Nobby the Bastard]

My exup had valve seat recession. This is why valve clearances tend to get smaller.

It will get to the point that the engine suddenly won't start because the clearances when warm are negative when cold so valves are always slightly open.
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
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