classic motorcycle forum
Motorcycle Discussions => British Bikes => Topic started by: peteR on March 28, 2008, 11:59:08 PM
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Some advice please. I have a 1968 Triumph T100SS in pretty good condition all round. It has had some new silencers added at some point in its recent past. I noticed today that the left hand silencer is colouring. I have always believed this a sign of mixture weakness, but as I have a single carb, I don't see how this would affect one side only. Does anyone have any clues as to what I should be looking for here?
Many thanks for any replies.
PeteR
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Hi Pete
Is this something you have just noticed?
If it is and it's only on one side it might be something as simple as a spark plug.
Good luck
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Yes, I have only just noticed it. I have ordered a couple of spark plugs for it anyhow. I'll keep you posted. Thanks for the tip.
P.
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Make sure the manifold gasket isn't sucking air!!! Try spraying some aerostart around that area while idling to see if it affects the running!! Douglas
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Weak mixture and retarded ignition are generally the two main causes of 'blueing' because the combustion is not complete when the exhaust valve opens. I am not sure what kind of ignition system your bike has, but if it is controlled by cam and points there are possibilites of cam or spindle wear causing an imbalance in ignition timing. If it has twin points variation in the points gap could cause the problem.
There are two other possibilities :-
One is a 'tight' clearance on the exhaust valve of the offending cylinder causing the valve to open early.
The second is a leaking or burning exhaust valve on that cylinder.