M38 primer pump

Post by **wesk** » Sat Sep 09, 2017 8:50 pm

My money says the interior of these primers were coated or filled before wrapping with the same petroleum based preservative fluid the carbs, fuel pumps and other fuel system parts were preserved with. That is most likely the dried up material causing the spring loaded balls to stick to their seats.

radtech · Post by **radtech** » Sun Sep 10, 2017 5:20 pm

I examined the cylinders and the discharge ports after removing the ball checks and there was no residue of any type in the cylinder or the port as that was my first thought.

Post by **wesk** » Mon Sep 11, 2017 12:32 am

You are probably not seeing any of the evaporated petroleum products but there is some colorless residue that always stays behind. I doubt very seriously that those little 00.02 oz pressure springs are pressing those steel balls into those brass housings and welding them shut.

The two new ones I have here both had traces of a preservative inside the plumbing and both balls were easily removed.