Limp Mode 90hp Johnson Ocean pro

Hi There, has anyone come across the johnson 90hp going into limp mode when you run it for a time above 4000rpm? When this happens a alarm sound and the temp light comes on, however itis still pumping water strongly. All i do is shut the engine down and restart then she's fine. If I run at 3800rpm it will run all day.

Re: Limp Mode 90hp Johnson Ocean pro

Sounds like fuel restriction alarm.My 150 ocean pro always did it.The breather for the tank was at the back so the fuel would fill the breather and pressurize the tank.Yours could be same or fuel pump failing.

Re: Limp Mode 90hp Johnson Ocean pro

Sorry mate missed the bit about temp light.Have you checked the thermostats?

Re: Limp Mode 90hp Johnson Ocean pro

you are going tinto SLOW mode, your motor doesnt have the fuel restriction alarm, only the V6 modles of the same name had that feature..

you can run because two things happen....

your temps drops below 207 degrees F AND
you turned the key ioff, then back on...

if BOTH of those things dont happen, then you will be stuck in slow mode, which shouldnt allow you to rev past 2500 rpms

I have a similar motor and experienced that problem

you need to fix the source of your over heat issue!!!!!!!!!!

you if you ahve astrong stream for the tell tale

then you need to check and or just replace your thermostats

they are very easy on that motor...make sure you dont crack the plastic housing untightened and retightening

after tha, you should make sure you dont have a lean condition( which can cause over heating)

check your compression now, that you know you have over heated your motor!

good luck

bob

Re: Limp Mode 90hp Johnson Ocean pro

Hi Bob I have checked the thermostats and both open same time in hot water. The tell tale is spraying very strong. Could the fuel be a major issue as the primer bulb does not stay hard when the motor is running?

Re: Limp Mode 90hp Johnson Ocean pro

Check to see if the water exiting the block is hot. If it is not and you are getting an overheat then use a infrared thermometer ($29 at harbor freight) and take a temperature reading on the head near where the temperature sender is. There are references as to what that temperature should be below. You may have a problem with the actual temperature sender and when you reach a certain temperature (below overheat maybe) it is closing the circuit and telling the power pack to go into slow mode. I owuld not run the engine until you are completely familiar as to what you are looking for. Hopefully an experienced mechanic will comment on this, I am only a shadetree. BTW thermostats are cheap and if you already have the old ones out put new ones in. Keep the old ones on the boat, never know when you may need to limp in because one froze and shut water off from proper circulation.

Re: Limp Mode 90hp Johnson Ocean pro

The primer bulb is not supposed to stay hard with the engine running; it just becomes part of the fuel hose.