1972 65hp Alarm in control box?

[kwizz]

Had a few issues with my engine on last few runs, but one of them was the alarm sounding when WOT. I thought it was over heating but when checked the engine was hardly warm, tonight I tried just turning the electric on by the key without starting the engine and operated the throttle to WOT and the alarm sounded, is this right should the alarm sound?

Any help appreciated.

Thx.

 

[boobie]

Re: 1972 65hp Alarm in control box?

Sounds like you have a tan wire grounding in your control box from throttle movement. The tan wire when grounded is what sounds the horn. Take the box appart and look for any frayed or grounded tan wires.

 

[kwizz]

Re: 1972 65hp Alarm in control box?

Thank you very much. I will check in the morning.

 

[kwizz]

Re: 1972 65hp Alarm in control box?

Another thing, Would this tan wire grounding have any effect to the engines preformance i.e a type of shorting out making engine stutter.

 

[boobie]

Re: 1972 65hp Alarm in control box?

Your mtr didn't have QS or SLOW so it shouldn't effect running quality. The only thing on your mtr the tan wire circuit was for was to warn you of an overheat prob.

 

[kwizz]

Re: 1972 65hp Alarm in control box?

I know I shouldn't do this but breaking away from the original thread. Whilst yesterday the alarm sounded on WOT wether the engine was running or not, I had the boat out for a short run after removing the thermo switch wires and fitting a jumper as per the service bulitin, after about 5 mins of running the engine started to kick and buck about quite hard but only when in gear, idled smooth and fine.

 

[kwizz]

Re: 1972 65hp Alarm in control box?

I think all questions have been solved!!! Thx Boobie

I took the throttle control box out of boat and dismantled it, set the throttle lever to what would be WOT. When I offered the two sides of the casing together the arm which is connected to the throttle cable touches the outside of the alarm unit, which I guess is the grounding Boobie was talking about. Shouldn't be hard to fix that.

Also at the same time while checking the alarm fault which thanks to Boobie, I think i've found the problem with the engine jumping around yesterday. In the bottom of the control box there was some water (prob's from the rain we had) lying around the electric gear shift switch, and water has travelled along the wires and into the rubber cover where the connectors attach to the switch, on inspection it looks like the lower two terminals nearest where the waters leaked in have been shorting and jumping out of gear. I'll be able to dry it out and seal it all up. Only worry is if the jerking has caused any damage to the gearing.

Thanks Boobie.

 

[boobie]

Re: 1972 65hp Alarm in control box?

Glad to hear you found the probs.

 

[jay_merrill]

Re: 1972 65hp Alarm in control box?

Just an FYI item ... the SB item that you performed is in regard to the electric choke, not the hot horn. The hot horn sensor is located on the other side of the cylinder head, at the top, right position.

The hot horn is fed with voltage and only needs a ground to sound, so a short anywhere along the way will do it. If you ever change your ignition coils on this motor, be sure not to pinch the wire leading from the thermoswitch - this is a common source of shorts in this circuit.



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