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[roberto]

Hi all,I Wondered if any one could help with this,Some weeks ago it started with a faint tinkling,got worse when hot but not too worrying I thought,seemed to get a bit worse lateley,went for run today about twenty miles, seemed ok riding along,arrived home , much worse even on tickover, and quite rattley when revved,sounded a bit like tappets but i did check them when cold when it first started, sounds like a top end rattle, but i dont know.Its a 500,1200 miles,2004,used a lot on short runs,any input would be much appreciated,Thanks Bob H.

[PeteF]

Could be a few things but sticking valve comes to mind from your description, or a loose valve seat. I'm afraid it's "off with his head" to find out.

[Phil Ashbrook]

I had a top end rattle that perplexed me , at first I thought it was the rocker blocks so I bought the alloy Samrat blocks and drilled out the oil hole to the same size as the originals , the noise was still there so I bought the light weight hosts push rods ...and it was still there .
The head had been de-coked and was fitted with new valves and valve guieds + a few thou over size , I was having intermitent compresion problems so I pulled the head off and stripped it down and what did I find....the unblievable !
The guy who fitted the new guides had got his maths wrong and one guide
fell into my hand and the exhaust valve could be pushed out with one finger so I found my noise problem .
On the re-build I decided to go a general engineering machine shop as the old man who did the work sadly passed away in a race crash in Darwin , with the guides out I spent many hours porting it out seeing that the mass of alloy around the guide in the inlet and exhaust ports
could be removed and did the full race job with oversize bronze guides ,
larger valves The exhaust being the most needed as the former owner ran the bike on unleaded fuel with no valve saver juice so the valve was far too deep in the head , fitted the 535cc piston , race valve springs , high performance cams and ajuster spindles and basicly went all the way
even opening up the oilway paths and neoprean big end oil seal rather than the cork type and with the Amal concentric MK II I have a very powerfull ( 100% more than standard BHP ), it does not rattle it flys like a Bullet and with a straight through fake muffler this 1995 pr-metric Export classic is loud as this is Australia and the cops dont care with the large amount of loud chopper Harleys on the Australian roads , it's a pig to start cold so I bump start and so far have lived on roads with a hill..I should get a speedway bike starter .

[Norm]

Got a top end rattle in a 612 we got running today, can't imagine what it is, Ace cams, Ace piston,Hitch pushrods,Samrat rockers, Hitch competition valves. Tried standard cams, no cange, changed pushrods, no change,tried original rocker blocks no change. It clicks just after the inlet cam comes off the top, it has to be a valve issue but can't imagine what. I guess the head will have to come off again

[another Allan]

Hi Norm. I had this same noise when I had rebuilt my 625 with new cams, followers, cam spindles etc. I finally traced the cause to backlash in the cam gears. As the valve spring tension started to release, the cam follower came down and a click was heard due to excessive backlash. A few minutes playing with the setting of the adjustable cam spindles to optimise the clearances, and everything was fine.

[Norm]

Hi Allan,
first thing I thought of but no joy, I am now of the opinion that it is something happening with the valve springs on the inlet valve