Water temp sender size F150 ?

[NW Drifter]

Hi guys, I want to order a sender for an aftermarket water temp gauge for my yamaha 2007 F150 outboard. I can't find any info on how big the bolt size is.

I see 1/2" NPT senders but wouldn't it be metric?

Is this the right one?

Sierra Tmp Sender Mc.1/2-14 18-5898

[fairdeal]

I believe the hole you will be using is M14 x 1.5 thread
your sender either 1/8" or 1/4" NPT
and then an adapter bushing
which you can probably get at an auto parts store

yamaha does have several adapters but IDK what the female thread is

MAR-WPRES-AD-TR Yamaha Water Pressure Adapter Assembly

63P-8366C-00-00 YAMAHA CONNECTOR 2

btw, there was a thread recently about that filler plug you'll need to remove
and the possibility that it tears the aluminum threads on its way out
you might want to see if it is actually removable before you go any further...

[boscoe99]

One other way is to remove the plug and then drill and tap it for the size of the sender that is compatible with your gauge. Or, drill and tap the plug in situ in which case there is little risk of damage to the threads on the motor. If this is what you do I would recommend getting the sender with 1/8th NPT threads.

[fairdeal]

?
I blinked and Boscoe withdrew his suggestion of a surface mount sensor?

that's what i went with, on my 2006 F90

FARIA INSTRUMENTS Cylinder Head Temp Sender | West Marine

I had tried backing out the plug,
but when I got up to trying it with a 20" long breaker bar
and it still wasn't budging....

[boscoe99]

?
I blinked and Boscoe withdrew his suggestion of a surface mount sensor?

that's what i went with, on my 2006 F90

FARIA INSTRUMENTS Cylinder Head Temp Sender | West Marine

I had tried backing out the plug,
but when I got up to trying it with a 20" long breaker bar
and it still wasn't budging....

I withdrew the suggestion when I started to realize the OP has an F150. I used a surface mount sender in my Mercury two stroke and it worked OK but then I was not sure where it would be mounted on an F150 so I retracted my comments.

The plugs are tight but they can be removed. I removed two of them on my F200, one for the temperature sender and one for the pressure adapter. I also removed the same size plug on other models so as to install an EGT probe and an oxygen sensor. Yamaha seems to use some kind of sealant on the plug. Might be the red lock tite from hell.

Maybe a bit of heat from a torch will soften the sealant and allow easier removal of the plug. Or maybe just someone more manly.

[fairdeal]

I used a surface mount sender in my Mercury two stroke and it worked OK but then I was not sure where it would be mounted on an F150 so I retracted my comments.

I just put the sensor under one of the bolts of the exhaust cover - seemed to give meaningful values.



(I think I used a little "heat sink grease" under it - just cause I had some handy)