50 HP Johnson ?

The motor is a friend of mines and is an 87 or 88 and is the VRO model. The problem was from what he said it would run and cut off at a few minutes and would die out when running. Now after not cranking it over the winter he is looking to get it fixed, as of now it will only crank when revved really high and cuts off in a few seconds. This is a list of stuff he already repaired (but still has the problem) if it helps eliminate anything. Thanks for any and all help.
Motor:

  • R/p spark plugs
  • R/p power pack
  • R/p all fuel lines
  • R/p tale-tale water line from engine block to bottom of pan. That pee’s water out motor
  • Rebuilt fuel pump
  • Rebuilt electric prime start solenoid (AKA) choke cold start
  • R/p cam roller on throttle linkage
  • Rebuilt carbs with new carb kits
  • R/p throttle and shift cables
  • R/p battery cable with a brand new yamaha cable/ old cable not long enough to reach console
  • R/p the inline fuel filter on engine
  • R/p gear lube in the lower unit
  • compression check #1 cylinder 120psi #2 125psi

17ft Key west

what is the spark doing
I know he replaced the power pack, but what is it actually doing

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