70hp steady alarm at high RPM - not heat or VRO - possible fuel restriction?

[onehunglow]

1987 Evinrude 70hp

I am getting a steady alarm even when engine is just started and cold (I also have a temperature gauge) as soon as RPMs go up (just with high-idle lever up) that goes out when engine goes down to idle (so I doubt its a short)

Pisser is good...tested temp sensor....tested VRO sensor...its neither of those

I have read that a steady alarm that goes on only with high RPM and off with lower RPM is a Fuel Restriction alarm...but I am not sure if my motor has that feature...but the symptoms sound like that. It does not feel like anything is misfiring or straved at high RPM but I am worried because of this alarm.

Is this possible? How can I check for a fuel restriction on my 70hp ?

 

[seahorse5]

Re: 70hp steady alarm at high RPM - not heat or VRO - possible fuel restriction?

There is no fuel restriction alarm on a 70hp. A continuous alarm is normally an overheat condition on that motor.

The electronics inside the oil tank pickup sender can give wierd signals. If you are sure the engine temp is OK, disconnect the oil tank wires at the motor and see if the alarm quits.

An overvoltage charging problem also can affect the alarm system.

 

[onehunglow]

Re: 70hp steady alarm at high RPM - not heat or VRO - possible fuel restriction?

Its definitely NOT an overheat since it can happen when I start the motor cold and just raise the high-RPM lever..

I already tried disconnecting the high-temp sensor - alarm continues
I disconnected the disconnect of the VRO black wire that runs into the motor - alarm still goes

Yes I thought it must have been a short somewhere ...but if it was, then the alarm would be going off even at idle

This is very strange since it goes off as soon as I up the RPMS

 

[Neil74]

Re: 70hp steady alarm at high RPM - not heat or VRO - possible fuel restriction?

Try disconnecting your throttle cable at motor an opperate the throttle from the engine. If there is a short when moving throttle it will isolate it to motor or throttle housing.

 

[onehunglow]

Re: 70hp steady alarm at high RPM - not heat or VRO - possible fuel restriction?

I just noticed that there is something wrong with the charging system....I am only getting 12.6 volts at the battery when running (when it should be upwards of 16v) ....so THIS is a problem

But can THAT be causing an ALARM????

 

[onehunglow]

Re: 70hp steady alarm at high RPM - not heat or VRO - possible fuel restriction?

Yes ...its a faulty rectifier for sure....disconnected and performed Jim Reeves tests....its definitely toast

Could THIS be causing an alarm at higher idle?

One clue was that my tach was not reading anything ...could this mean a faulty STATOR too? Does the tach pick up 12V AC from the stators ....or 12v DC from the rectifier?