1991 30hp Johnson Throttle problem

Hello, first i would like to apologise im new to boating and dont know much about engines of any type.

Now to my problem, i purchased the 30hp last winter, the seller ran it fine in a barrel, then last week i took my boat out for the first time, started the engine first turn, left the dock and built up the speed slowly, i ran at full throttle for 10mins then i back off the throttle so i could take in some fishing. The throttle backed off ok however it wouldnt pick up revs again, i had to limp back to the dock at idel speed. i then changed the plugs, the top one was ok and looked healthy, the bottom one was wet as if it had flooded.

I got home and played around a little, bought new plugs checked all linkage was good then took it out again yesterday, the same thing happened again, ok at full throttle then when i back it off it dosent pick up. Can anyone please help!!

Much appreciated, Mark

Re: 1991 30hp Johnson Throttle problem

Welcome to iboats Mark!

Is there water coming out of the tell tale hose? Does the motor smell hot? If you can't put your hand on the head by the spark plugs after running, it is probably overheating. The motor has a temperature sensor that will limit the motor to 3000 rpm. if it is overheating. The motor should run at 145 degrees when it is warmed up.