Sorry Rick, I was addressing a gasser governor with my above post. Please disregard my earlier comments.
There is a PLASTIC governor ring in your Roosa Master pump that disintegrates over time and leads to symptoms you are describing.
Below is a quote from JDEMARIS on another forum:
"Shattered plastic governor dampener ring sends small pieces of plastic all through the pump and often creates overly high housing pressure - which result in the problems like you describe.
Often leads to engine shut-down.
I had to fix many - out in the woods and field when I was a Deere mechanic. Deere,Case,IH, Ford, AC, Hercules, et. al. all use some versions of the same pump.
A complete seal kit with a new dampener is $12. A person with experience can pull the pump all apart, reseal and put back togeher - in one hour.
There is an updated dampener that can be installed and it will never come apart again - for an extra $40 (EID retainer). Stanadyne used it in all the pumps after 1985.
If your pump has high hours - you can assume it will need a few more parts than just the seal kit - if you want to replace them while apart. Main wear items are -
front drive bushing where the shaft-seals ride - new one cost $10.
fuel metering-valve - $12
fuel pump vanes and liner - $16.
That's about it - most pumps that get "rebuilt" at a Stanadyne-certified only get those parts plus a seal kit. $50 in parts total. Cleaned up, put on a test-stand, fuel delivery and timing advance checked - and then a $350-$650 repair bill.
If you are careful - no adjustments get altered. You can, however, check the max. fuel delivery setting while apart with a 2" micrometer.
Timing advance can be checked on a running machine with a $8 plastic timing window - or a conventional timing light hooked to a piezo-pickup on an injector line. "