The FSM sez "Inspect insulator. Replace if permanently bonded gasket material is bunged up."
Sweet! Thanks Jim! I just found your previous post on this topic. Now all I need is a lathe....and a 4 jaw
"The OE gasket material doesn't dry out & crack. It gets vandalized by people armed with gasket scrapers. The replacement gaskets dry out & crack.
The FSM says something like "Remove carb, inspect insulator block. If insulator gasket is damaged, replace insulator." Note that is does not say replace insulator every time or scrape off baked on gasket. It says inspect, replace only if necessary.
Case study of 1: The insulator on the dyno engine is 35 years old and has had 2,500 different carbs bolted to it over the last 20 years, no problems. Clean, flat carb on clean, flat gasket=good seal.
If an insulator block has OE gasket that appears to be too stiff to get a good seal, soak it with b'laster before installing. It will absorb the solvent and soften slightly.
When the insulator has been fuggled with a gasket scraper, it should be milled flat, than a new gasket(s) is shellac'ed to the insulator block, a little grease is brushed on the intake & carb base, then insulator & carb installed to clamp the new gasket between two flat surfaces while glue sets.
HTH
FJ40Jim,
Apr 6, 2016"
