[TR] TR6 evaporative filter - function or setup question

[Randall]

> Why does this have such a huge impact on the engine (especially idle)
> when the pipe to the valve cover is unplugged?

Well, it's basically an intentional vacuum leak.  By blocking off the flow
into the emission ports on the carbs, you are changing the mixture.  

In theory, though, the crankcase should be a dead end, so it should quickly
pull a few inches of vacuum and then go back to where it was.  It should be
the line to the carbon canister that makes a big, permanent difference.
Could you have tired rings, or some path for air to get into the crankcase?
Wrong filler cap, perhaps?

BTW, you do have the restrictors on the ports, correct?  Probably, for a
triple setup, you should really have smaller restrictors to keep the
'emissions' airflow the same relative to the flow past the throttle plate.

-- Randall