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Re: Imminent Catastrophe?
Posted: Thu Oct 04, 2018 11:23 pm
by SPRIDDLER
Braaap wrote:We should never stop learning!
Relevant or not.... all knowledge is a step forward.
That's very true.
However, much of the shared 'wisdom' is like folklore and has been handed down over generations of fettlers. Sadly, too many of those sages are no longer around, but fortunately their knowledge continues to be passed on.
Re: Imminent Catastrophe?
Posted: Fri Oct 05, 2018 11:42 am
by BobbyG
My '55 16MS developed a 'rattle' from somewhere up front several weeks ago. Nothing seemed to be loose. Checked and adjusted ALL the chains; tappets etc. to no effect. Removed front wheel to check brakes and drum - all ok. A mate suggested the springs in the front forks rattling... no oil? Drained and refilled. THEN... just happened to brush against the number plate on the front mudguard and something rattled. Turns out it was the Tube Fork Cover, bottom rattling about. Simples!!
Re: Imminent Catastrophe?
Posted: Fri Oct 05, 2018 2:27 pm
by Expat
clive wrote:Another possibility as well as valve bounce suggested by Janet is that the hairpin valve springs are rocking as they operate. I have had this problem with the spring lifting at higher revs, it then taps on the underside of the rockerbox cover before settling back down, each time the valve opens. If this is the problem there will be witness marks on the inside of the rockerbox cover. I think old stock springs made for the first models with hairsprings had slightly shorter tangs. These fitted into drilled holes in the seat for the valve spring part number 010017 (see 1949 parts list) this required a special c tool to extract and was a fairly lengthy process. By 52 the seat for the valve spring had changed to an open tray 018275 and the part numbers for the springs had changed as well, I believe because the tangs were longer. Even the illustrations in the parts list appears to show longer tangs. The later system allowed the springs to be installed, again with a special tool, in one movement. My experience was I could fit the spring without the tool. I sorted it by fitting the early trays as I had those but not the later springs.
Clive,
Here's pics I took early last year when the head was off mainly to cure pushrod tube leaks. Seems to show the later springs and seats from what you were saying. Can't see any marks inside the rocker cover and the rattle was around back then.
Also, on the oil loss front, pic shows a small plastic bottle I wedged up over the breather pipe. Not much in there after a ten mile run I would say. That's not where the oil loss is.
Re: Imminent Catastrophe?
Posted: Fri Oct 05, 2018 3:44 pm
by Expat
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Re: Imminent Catastrophe?
Posted: Fri Oct 05, 2018 3:46 pm
by Expat
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Re: Imminent Catastrophe?
Posted: Fri Oct 05, 2018 3:49 pm
by Expat
D0BC578E-FB4B-4071-9C9A-53F1AB7DD193.jpeg
Re: Imminent Catastrophe?
Posted: Fri Oct 05, 2018 3:53 pm
by Expat
SPRIDDLER wrote:Braaap wrote:We should never stop learning!
Relevant or not.... all knowledge is a step forward.
That's very true.
However, much of the shared 'wisdom' is like folklore and has been handed down over generations of fettlers. Sadly, too many of those sages are no longer around, but fortunately their knowledge continues to be passed on.
Thank heaven for that. It's very much appreciated by all of us.
Re: Imminent Catastrophe?
Posted: Fri Oct 05, 2018 6:56 pm
by raffles
I had a similar noise for thirty six years and 36.000 miles never could find it. rebuilt the engine last winter. 3.000 miles done so far
this year and YES the noise is still there.I have a friend with another 500 single. Same noise. If you discover how to cure it, do post
and tell us if not, use the rattle as a gearchange indicator and dont worry about it.
Tony
Re: Imminent Catastrophe?
Posted: Fri Oct 05, 2018 7:40 pm
by Janet
Maybe it's your teeth chattering.
Re: Imminent Catastrophe?
Posted: Fri Oct 05, 2018 8:02 pm
by raffles
What an observant lady you are. no flies just marks where they have been
Tony