ZRX top end rattle under load

[Gazza M]

I've got a rattle that's developed on the bike...

I noticed the rattle soon as I came off the motorway and onto slower roads, it sounds like it is coming from the top left hand side of the engine only under load - so if I shut the throttle and let the engine run down the rattle isn't there, but when I accelerate it is quite loud, and is faintly audible when I'm sitting at constant speed. at first I though it could be an exhaust gasket that's given up, but it sounds more of a slap than a blow so I'm thinking CCT/valves are responsible. It's just about audible when the bike is idling in neutral - video is here https://youtu.be/MMgvFZa_bao

I've just come down to London from Cambridge (60ish miles) so am an hour away from home... do you reckon I'll be OK taking it back home? I don't really want it blowing up halfway down the motorway!

If there is someone in southwest London that would be able to take a quick look sometime tomorrow that would be ideal...

TIA
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Past: '07 YBR125, '00 GPZ500S, '99 ZRX1100, '98 CBR600 track bike, '97 ZX9R
Present: '05 R6 track bike, 140 pit bike

[.....]

Video is private.

[Gazza M]

Whoops... shouldn't be now.
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Past: '07 YBR125, '00 GPZ500S, '99 ZRX1100, '98 CBR600 track bike, '97 ZX9R
Present: '05 R6 track bike, 140 pit bike

[.....]

Someone who knows a lot more will be along shortly but I wouldn't be riding that anywhere.

Have you checked the oil level recently?

[Ariel Badger]

Cam chain/tensioner.
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Bikers make great organ donors, get 115 on your licence today.

[misscrabstick]

plugs not loose?

[Gazza M]

Oil level is fine, can't get to the plugs as I can't really get the tank off as it is - parked on the road outside my girlfriends house. I've hada plug go before on an old bike, but that was a lot louder!

Camchain/tensioner was my first thought - reckon I'll be ok driving home if I nurse it? There doesn't seem to be any loss of power at the moment but I don't have many options with getting it back...
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Past: '07 YBR125, '00 GPZ500S, '99 ZRX1100, '98 CBR600 track bike, '97 ZX9R
Present: '05 R6 track bike, 140 pit bike

[buell1203]

take off the alternator and tightened the alternator drive flange nut which become very loose.

[Gazza M]

Sorted. Turned out one of the exhaust gasket thingies was a bit loose so it was blowing through a bit and making a bit of a racket! Dunno quite how it worked is way loose, the bit that unscrewed itself was the studs going into the engine rather than the nut on the stud. I tightened it up and the whole thing is a lot quieter! Checked over the CCT to but thats all good.
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Past: '07 YBR125, '00 GPZ500S, '99 ZRX1100, '98 CBR600 track bike, '97 ZX9R
Present: '05 R6 track bike, 140 pit bike

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