False buzzer alarm

[Sloth608]

I just recently purchased a new to me 1987 120hp Johnson outboard. Every once in a while when I go to start my engine cold and the alarm buzzer will stay on constantly before I even crank the engine and then stays on untill I get the engine warmed up. After 5-10mins of the motor running sometimes the buzzer shuts off sometimes it doesnt. I did some trouble shooting with the key turned in the on position and the buzzer giving me a false reading I disconnected the wire plug going into the vro oil/fuel pump and it the buzzer stoped! However, with the key still turned I went to plug the connector back in and it stopped buzzing altogether, key turned or not. My question is, did I fix it or not? Is it possible unplugging and plugging back in the connector maybe cleaned a connection? Or is there a more serious problem I am not seeing here that would cause this false alarm to turn on and off speratically?

 

[Joe Reeves]

If this condition returns.... the buzzing (beeping) starts as soon as you tun the key to ON.... remove the TAN wire from the horn.

If the beeping continues with that TAN wire removed, the horn is faulty.

If the beeping stops instantly, one of the sensors at the engine is faulty (2 heat sensors - VRO sensor - oil tank sensor).

I know you've tried the VRO.... try the others also.

 

[Sloth608]

Thanks for the answers! I will be taking it out later this week and I will see if i get another buzzer warning!

 

[Sloth608]

Im not so sure its a false buzzer anymore. I got it out back on the water the last couple of days. I have not taken the throttle box apart to trouble shoot anything in there yet. The symptoms seem more predictable now. Startup is the same with the buzzer buzzing before I even crank the engine. Stays buzzing while im warming the engine with the fast idle lever pulled up (around 1500rpms). As soon as I get the motor into gear the buzzer shuts off almost instantly. It did this every time 5 times in a row. Today the motor did something that I have never seen it do before. It never smoked when it started cold and it normally does. Then after about 5 second it sneezed or something then bam it started smoking like a chimney. Is it possible the buzzing is warning me that the vro is begining to fail? Im currently pre-mixing 100:1 in tandem to the vro just in sheer paranoia the vro might fail so I expect it to be smokey on statup. If it helps any I also put my hand on the engine head after running it pretty hard to see if it was possibly overheating and I could hold my hand there for about 5 seconds so I would say its pretty safe to rule that out.