weber and timing help please

is anybody else having problems where they have to advance there timing a lot to get there truck to run with the weber carb I'm lost never had this sort of problem before with the 4 weber Mazda's I have had in the past but the truck will not run with the timing set dead on could this be a burnt valve? bad compression?

I run a Weber 32/36 DGEV on my B2200. I use the stock timing data. If you have any sort of vacuum leak with that Weber/its adapters (did you check the adapters all for absolute straightness, use brown goop sealant on the gaskets), that will affect the timing advance.

I think I'd recommend to set the idle timing with the vacuum line and distributor inlet plugged. But you still need to address any of the known Weber vacuum issues.

I will second the brown goop sealant.... it's called PERMATEX Indian Head Gasket Shellac Compound.

Anything else seems to allow vacuum leaks.

I actually use Permatex Aviation, from O'Reilly or Ace Hardware.