Re: 9.9 Johnson Carb Question

[Don]

Huh, didn’t realize the early models had different heads for the 9.9 and 15hps….I’m guessing that they eventually superceded to the same part number….
The easiest way to determine if you have the old vs new style head is to look at the thermostat water cover. Early models will have a water cover that is straight on its stb/right side. Later model covers were scalloped out around the plugs. These early models had several repair/update kits to combat plug fouling and ignition woes. There is no need to update the older style heads unless you are having plug fouling problems….