Is this fuel pump oil switch NO, and 1/8" NPT thread?

[sdowney717]

OEM Quicksilver/Mercury Fuel Pump Oil Pressure Switch 87-864252A01 8M0210755

OEM Quicksilver/Mercury Fuel Pump Oil Pressure Switch 87-864252A01 Please confirm fitment of MerCruiser parts with your serial number. Photos and descriptions provided via Mercury may not always be accurate. All of our Mercury parts are sold and priced EACH.

powerboatsupply.com

Anyone know what oil pressure activates it to closed?
Is there a cheaper price somewhere?

 

[alldodge]

Anyone know what oil pressure activates it to closed?
Is there a cheaper price somewhere?

5-7 psi will close the switch

 

[Fun Times]

Going off memory I believe the spec in the book is 4 psi.

 

[sdowney717]

I am more worried about thread size, as if it is metric, I can't use it.
If it is 1/8" NPT then that's good. If it was used on GM350 engines, for a long time, it should be US standard pipe thread. I would not be using it on a MerCruiser engine.

 

[alldodge]

It's 1/8 NPT

 

[sdowney717]

Thanks good to know. I currently have a 3 terminal GM vega switch, but have no rubber cover socket. I would prefer to have a better attaching plug, this switch I could work with. My GM switch turns on a relay and the relay runs the pulse pump. And it's no trouble to run the pump when key turns to start. I did find cheaper versions of this switch and plug on Ebay,

 

[Bt Doctur]

https://www.ebay.com/itm/1571548867...90&itmmeta=01K1CPFYBKBD92QH8245PMYH1Astandard Parts makes replacements and its better on the contacts if you route it thru a cube relay. Sometimes excessive pump current burns it out

 

[Scott06]

Thanks good to know. I currently have a 3 terminal GM vega switch, but have no rubber cover socket. I would prefer to have a better attaching plug, this switch I could work with. My GM switch turns on a relay and the relay runs the pulse pump. And it's no trouble to run the pump when key turns to start. I did find cheaper versions of this switch and plug on Ebay,

sounds like someone added the electric fuel pump to your boat as the first switch you showed is the OEM merc one.

Typically the three prong one is used as a universal fit when adding a electric FP or in partial replacement engine packages like Michigan Motorz offers. Heres what they offer aftermarket and OEM

Michigan Motorz LLC

michiganmotorz.com

 

[sdowney717]

I did that 15 years ago on my twin engine v8 inboard boat.
At the time I used the GM switch, but never had a female socket plug, which makes it harder to reconnect properly. So went looking for an update I could do in the future and a cheaper part as that GM switch is maybe $40 by itself.

It is wired into a cube relay to run pulse fuel pumps.

 

[sdowney717]

sounds like someone added the electric fuel pump to your boat as the first switch you showed is the OEM merc one.

Typically the three prong one is used as a universal fit when adding a electric FP or in partial replacement engine packages like Michigan Motorz offers. Heres what they offer aftermarket and OEM

Michigan Motorz LLC

michiganmotorz.com

This is a similar switch with 1/4 thread, mine is 1/8 thread. But I have no female socket for it.

Oil Pressure Safety Switch

michiganmotorz.com