93 johnson fuel restriction

[maxgun]

I have an ongoing problem. I have a 93 johnson v4 90 hp ,on a 18 foot four winns bowrider. I can drive around at full speed, it does fine. I can pull my son on a wake board and it does fine. When I put the big tube on the back, the horn goes off, solid sound. I shut it down and wait a wile, try again, then the same thing happens. The sticker on the side of the boat says, solid horn is fuel restriction. Over the last months I have changed the fuel filters changed a piece of hose I thought could have been kinked. Any ideas? could it be cloged injectors? If so can you use injector cleaner with the oil mixed fuel.Thanks, Ron

 

[rickdb1boat]

Re: 93 johnson fuel restriction

Solid horn can also be overheat.....

 

[maxgun]

Re: 93 johnson fuel restriction

If it is overheating, how can I tell? I do have a strong telltail. What can I check, or do?

 

[o/b tech]

Re: 93 johnson fuel restriction

The motor shuold also have a vro pump on it with a remote oil tank. If the vro does not detect a pulse from the pump, within a given number of tach signals it will also sound a steady alarm. To confirm that the vro pump is working properly, mark the level of oil in your remote oil tank and confirm that the oil is being used. If in doubt take it to your local dealer and they can perform an oil flow test on the pump. You may want to run a pre-mix fuel in your main tank until you can determnine the source of the alarm.

It is also not uncommen to have a faulty low oil sender in the tank to sound a continuous alarm. When the sender finally craps out the alarm sounds as soon as you turn the key on.

hope the info helps.

 

[o/b tech]

Re: 93 johnson fuel restriction

If you are in doubt that the water pump may be causing the alarm, have it replaced as a normal maintenance proceedure. Also, is the motor peeing a steady streem when the horn is going off?

 

[91cajun]

Re: 93 johnson fuel restriction

Based on your post I'd say it's overheat. On my motor solid warning horn is overheat. If you let it sit a while and start up again with no horn, most likely overheat. Is the telltalle peeing? Water pump last changed? Thermostats working?

I bought an infrared temp gun from Northern Tool so I could see how hot my motors were getting. You just point it at the heads when running and read the temp. Changed my impeller and thermostats and she runs cool as a cucumber now.

 

[91cajun]

Re: 93 johnson fuel restriction

One more thing. In my case the motor had been used in salt water. The old thermostats were caked with depostis. Has yours been run in salt water?

 

[maxgun]

Re: 93 johnson fuel restriction

I don.t know if my boat was used much in salt water. I have only owned it for two years. iwas told no. I do have a solid telltale, even when the horn is sounding. I replaced the impeller at the beginning of the year. What should be my next step to decide if it is lack of fuel, lack of oil, or an overheat? (or in my case, a loose nut behind the controles!)

Thanks, Ron

 

[91cajun]

Re: 93 johnson fuel restriction

Have you tried running the motor on muffs or in a barrel? Do you have the OMC manual for the motor? If not it's worth the money. My manual covers motors like yours up to 91. Horns are:

Overheat - continuous tone
No Oil - continuous short pulses
Low Oil - short pulses every 20 secs
Fuel restriction - continuous tone at or near full throttle.

That being said .... is the horn only going off at full throttle or does it continue after you shut down? If it is overheat the horn will continue to sound if you turn the key back on right after shut down and will stay on until the motor cools down.

 

[maxgun]

Re: 93 johnson fuel restriction

The horn stays on. So I now agree that it is an overheat problem. I changed the impeller to start the season. If I have a strong telltail does that mean that everything is allright with that . I am thinking that my next step is to change my thermostats. Now I have to find them , I don't even know if I have 2, or 4. Or top of engine or bottom, Someone told me If it was an EFI engine it is at the top, or regular at the bottom. Does that make any sense to anyone , and how can I tell what I have?