1993 Johnson 120 VRO won't run above 2200 rpm

[goss70]

I have a 1993 Johnson 120 VRO it runs fine at low rpm but will not get above 2200-2300 rpm. I just got it back from the shop, had all four carbs gone through. I took it out and it ran fine for about 10 min then started the same problem again. I got a fuel restriction alarm once for about 5 secs. Got it home and looked at all the fuel and oil lines and tested the VRO pump, hooked up a 1/4" line to the oil side and it pulled about an inch of oil in 4-5 cycles of the pump. The fuel side seems to be working fine, can see the fuel going through the filter, volume seems fine to me. Anyone have an idea.

 

[ezeke]

Re: 1993 Johnson 120 VRO won't run above 2200 rpm

Unless you added it yourself, you don't have a fuel obstruction alarm - that's from a vacuum switch on the V6 motors.

What you do have is S.L.O.W. that will kick in with your constant alarm when one of the engine cylinder banks overheats.

 

[soneal1]

Re: 1993 Johnson 120 VRO won't run above 2200 rpm

I think you have some type of power restriction. I would take a look at one of your coils for a possible broken wire or cracks or cracking around the case of your coils this is an indication of a bad coil .If one is bad that is enough to cause a ,built in safe power restriction .
VRO Horn Warnings)


1 - A steady constant beep = Overheating - The V/6 engines, possibly some others, have a fuel restriction warning which is also a steady constant beep.
2 - A beep every 20 or 40 seconds = oil level has dropped to 1/4 tank. (Late model engine = Every 40 seconds)
3 - A beep every other second = VRO failure, air leak in oil line, oil restriction, (anything that would result in a lack of oil being supplied to the engine).

 

[goss70]

Re: 1993 Johnson 120 VRO won't run above 2200 rpm

OK, it is a constant alarm only when the key is turn on but goes off when the motor starts, I thought it maybe low oil so I filled the tank, it only took about 1/2 gallon, it holds 1.5 gals. The motor seems to have the same water flow as it always has, I have not touched each side of the engine to see if one is hotter than the other. As for the coils, is that the electrical component that supplys the spark to each plug - my motor has 4 of them - if the wires are good - how do you figure out which one or more is bad?

 

[actionpaintball]

Re: 1993 Johnson 120 VRO won't run above 2200 rpm

Make sure your tank(s) are vented properly and not causing a vacuum fuel lock.

 

[jonesg]

Re: 1993 Johnson 120 VRO won't run above 2200 rpm

Its either ..

1.the temp sensors on the cyl heads.
2. or the VRO sensor.


1. turn key on.
2. disconnect sensors and the beep should stop.

if you disconnect a sensor and the beep stops. then touch the wire to the block and the beep sounds that would tell me that particular sensor is bad.

If you disconnect them and beep continues then look for chafed wiring.
Could be a blown isolation diode too in the harness.

 

[soneal1]

Re: 1993 Johnson 120 VRO won't run above 2200 rpm

If your motor is a v6,then you should have one coil for each spark plug .the coil gives each plug its spark. cracks on or a round the coil case is an obvious indication of a bad coil. pull off each spark plug wire away from the spark plug and see if you can see a spark jump from the wire,by putting the wire next to a screw driver. do one plug at a time . good luck

 

[ezeke]

Re: 1993 Johnson 120 VRO won't run above 2200 rpm

A 120 is a V4.

Your horn has a test circuit that sounds the horn once when you first turn on the ignition.

Any horn after the test circuit beep is a warning from either the VRO or from the temperature switches. The only constant alarm on the V4 alarm circuit is for an overheat.

Ignition coils can cut in and out when they are failing, so the only way to be sure that they are not the problem is to use an inductive timing light while running the boat (a two man job) unless you have a test wheel and test tank. Ignition coils can fail to work due to poor wiring, especially if the grounds are waek.