[TR] Overheating issue

[Randall]

> 	  Incorrect timing.
> 
> 
> Freshly timed last week

Not to belabor the point, but there is a lot more to timing than just the
usual initial ignition timing adjustment.  There are two different
mechanisms that dynamically adjust ignition timing to suit current
conditions; either one can go wrong.  Valve timing is also important.

Same thing applies to the mixture adjustment; the book procedure assumes
that all is well with the carbs and setting mixture at idle will result in
correct (more or less) mixture under all conditions.  I've seen some very
persistent overheating problems that were caused by the jet and/or needle
being invisibly worn, causing the mixture to go rich at idle.  Then when
adjusted by the book, the idle mixture gets corrected, but the mixture at
higher rpm is too lean.

Any kind of modification, like tubular exhaust or modifying the carbs "for
better flow" can cause the same problem.

-- Randall