LD340 Can’t Get The Carb Base To Seal

Also- those bolt holes for the carb mounting.
Make sure they were never drilled or bolted thru to the intake plenum. I’ve love all my LD340s BUT one I had a terrible vac leak. Turned out one of the bolt holes were over tightened with too long of a bolt and cracked the bottom of the hole. When I bolted my TQ on it I had a leak I could discover with carb cleaner, heard it whistle but only found it with a flashlight from under the plenum and in a dark room. The hole was in the holes o was not using.