Loss of power

[ttowner50]

94 Johnson 120hp
My motor will loose about half of its power on occation. Sometimes when it is first started or maybe after it has run for a while. It will lose power while running and regain power after a while or maybe it will run bad all day, or maybe it will run good all day. There seems to be no pattern to it. But there is a big difference in the power when it is running bad. Repaced 2 power packs, replace plugs every year, replaced wire connectors, gas has no water in it, use gas stablizer, cleaned filters. Anyone have any other ideas? Would appreciate your help.
Thanks

 

[Jayboid]

Re: Loss of power

When it is running poorly, can you temporally get more power by having someone squeeze the fuel primer or by engaging the choke?

 

[tashasdaddy]

Re: Loss of power

when and what was the last service done on it?

 

[Chris1956]

Re: Loss of power

TTowner, Does it have spark to both cylinder banks when it loses power? If not, the overheat sensor may be malfunctioning or the motor is overheating.