TOPIC: Mercury switch, where does it go?

When I pulled the starter off my 650 (1973), I found the mercury switch

laying behind it, not hooked to anything. I was able to trace it on the wiring diagrams, and I understand what it does (and why it's not functioning on my motor since it isn't grounded).

The question is, where on earth is it supposed to be mounted? I can't find anthying within the reach of the wire that it looks like it is suppose to be mounted to...

On my '63 1000, it's removed, but used to go on the port side of the powerhead. I'm at work and don't have a pic. There's a place for it to go on mine.

Frank

my 63 650 also has it on the port side of the motor. the cover plate has a slot that the switch fits into.

heres it is on my 62-700. ron

The newer motors had it on the front under the front faceplate. On that bracket in front of the carbs.
Conrad

On the parts break-down for the '73 650 3 cyl it appears that it was probably originally mounted on the port side exhaust cover.
Unless there is a terminal block there though, it is a long ways away from the switchbox for such a short wire. (one wire goes to engine ground - the other goes to the proper brown terminal on the switchbox. (there might be (2) brown terminals - one for the tach sender - one for this thing - so be careful when reviewing the wiring diagram)
There might be a picture in a manual regarding adjusting the port side throttle linkage that it might be visible.
The thing just needs to be mounted most anywhere in a way that the mercury stays down - away from the two contacts - until the motor is tilted up.
When the motor is tilted up it kills the ignition.
Don't buy a new one - I'm sure I have enough of them here to service North America.

They are a safety switch and although a lot of folks remove them or dis-connect them - you'll wish you had it connected if the Merc decides to join you in the boat when it wasn't invited.
Hitting dead-heads, snapping swivel housings at the tilt tube, improperly bolting down the motor to the transom, are just a sample of the reasons why they really should be wired in once trouble-shooting has been completed, etc.
Thom

They are a safety switch and although a lot of folks remove them or dis-connect them - you'll wish you had it connected if the Merc decides to join you in the boat when it wasn't invited.

WIRE IT IN.....Listen to the Doc, 2 years ago I was running @WOT down river in our skiff, hit a submerged deadhead cottonwood tree, the 25hp yamaha flipped into the boat on to the passenger seat beside me , prop facing me, still running & moving towards me.
That couple seconds fumbling for the kill lanyard seemed like an eternity, almost makes me shake writing this, another couple inches it could have carved me up
although not stock this yammy is now wired with a Mercury, mercury kill switch

don't quite understand why it broke loose from the transom. i hit a log in the hudson last year and it just flipped up and then dropped down. the only way it could break loose is if it was in the lock position.

Dr_Frankenmerc wrote:

On the parts break-down for the '73 650 3 cyl it appears that it was probably originally mounted on the port side exhaust cover.
Unless there is a terminal block there though, it is a long ways away from the switchbox for such a short wire. (one wire goes to engine ground - the other goes to the proper brown terminal on the switchbox. (there might be (2) brown terminals - one for the tach sender - one for this thing - so be careful when reviewing the wiring diagram)
There might be a picture in a manual regarding adjusting the port side throttle linkage that it might be visible.
The thing just needs to be mounted most anywhere in a way that the mercury stays down - away from the two contacts - until the motor is tilted up.
When the motor is tilted up it kills the ignition.
Don't buy a new one - I'm sure I have enough of them here to service North America.

They are a safety switch and although a lot of folks remove them or dis-connect them - you'll wish you had it connected if the Merc decides to join you in the boat when it wasn't invited.
Hitting dead-heads, snapping swivel housings at the tilt tube, improperly bolting down the motor to the transom, are just a sample of the reasons why they really should be wired in once trouble-shooting has been completed, etc.
Thom

I had no intent to remove it (still connected to the switchbox in the appropriate place), I was hoping to put 'er back the way Merc made her. It needs a little TLC on the wires but still seems to work fine. I'll look around on that front bracket tonight and see if I find anything.

On a side note, since you mentioned the tach wire - I was reading somewhere that in order to make a tach work on these motors, you have to take the brown wire off the switch box and reroute it to the rectifier over on the port side - that doesn't make sense to me, is that true, or was there supposed to be a factory jumper on there?

don't quite understand why it broke loose from the transom. i hit a log in the hudson last year and it just flipped up and then dropped down. the only way it could break loose is if it was in the lock position.

different boat than yours......like so many old boats it had dryrot in the transom that wasnt visible....don't quite understand why you even question me?

well if you would of said your transom was weak...i wouldn't of questioned you. however reading a post where someone says they hit a submerged deadhead and there motor ends up in the boat, and not explaining the transom was weak, what am i suppose to think other than the outboard was in a locked position.

the only way it could break loose is if it was in the lock position.

I didnt realize I had to list the several potential problems that could cause the situation or the condition of the boat, the validity of the use of the mercury kill switch is the topic not whether a Yamaha could kick up hitting a deadhead.

you have a great day

thankyou...

Answer is that the switch belongs on the starboard side just aft of the starter on the upper bracket. Why did I not see this before? Because the PO had put the starter ground there, instead of to the lower case mount as it should be.

As it was


look what I found


As it should be