Got my 81 Westy with engine #8 transplant back from the 500 mi. check-up
last night.  I'm like a kid with a lollipop.  Can't wait for the weekends
to cruise and fish, and all the great things Westies are made for.

Only problem is a recurring problem with missing and stalling that still
seems to be there - intermittently.  I thought at first it was a cold
starting thing, but it doesn't happen every time, and with the head temp.
guage, I can pretty well follow the ranges.  At one time it happened on a
downhill when the engine was hot from running, but usually it occurs at low
head and engine oil temps.  My layman's guess would be that a valve is
sticking open periodically.  If this is true, 1) is it likely to go away as
the engine wears in;  2) will this cause any damage in the interim;  3) is
there an additive that anyone would recommend to test this theory.  I still
have some Marvel Mystery Oil (which is believe is basically fuel oil) which
used to do wonders for my carbureted 72 Westy.  Any thoughts appreciated.
No, I won't do anything until advised.  Thanks for your indulgence with my
ignorance.