LD340 Can’t Get The Carb Base To Seal

Your mechanical advance is stuck, that tach drive distributor is good trade bait. Check out Halifax shops he is a member here he always has rebuilt distributors for sale on the forum

That's what I was going to add........it's either stuck, OR someone used it as a race piece and locked it out. But since he's saying he gets no more than 10* I'm going with stuck. lol