1984 Johnson 115 not hitting top speed and once warm drops way back

[brucehick]

Re: 1984 Johnson 115 not hitting top speed and once warm drops way back

On a two hose pump, the pump is mounted directly over a pulse port and a gasket seals the pump to the block. The pulse goes directly to the back of the pump.
On a three hose pump, the pulse is supplied through a hose to the pump and it can be mounted anywhere by use a bracket.

Is there a physical hole in the back of the pump. I don't recall seeing one when I took it off

 

[Daviet]

Re: 1984 Johnson 115 not hitting top speed and once warm drops way back

On a two port pump there is a small hole on the back of the pump that mates to a hole on the block with a gasket inbetween.

 

[James R]

Re: 1984 Johnson 115 not hitting top speed and once warm drops way back

So far we have only discussed the fuel side. After all this it sounds like the ignition may be failing and shows when the motor heats the components. This is not uncommon. You need to check the sparks when the motor is good and warm. I use a timing light and hook it to each plug wire in turn as the motor is running. You could be losing the spark to one or more cylinders.