Reply To: 1999 johnson 9.9hp

[CHUCK]

.I would suspect ignition but there are a couple of easy tests I would try.  When running and before throttling up…..squeeze the primer bulb and note if it is firm.  It should be firm.

Then…..if you can insert in-line spark checkers into the spark lug wires…..see if you can observe a loss of spark when the missing occurs.  Hopefully you could do that in a barrel or test tank