Mercury 650 Temperature Sending Unit

[Ryche]

Im looking for a part number or link to someone who sells the water temperature sending unit for a 1974 Mercury 650 65hp. all the diagrams i look at it is not listed. Any help is appreciated. The unit that is currently installed in the engine is no longer sending and needs to be replaced.

 

[Faztbullet]

IMO Inlines run too cold for a temp guage...install a water pressure it works instantly. You will need a 0-15 psi one..

 

[GA_Boater]

I believe you will find out the sending unit unit is an aftermarket unit, not a Merc OEM unit.

 

[Ryche]

Ya have been looking at pressure kits too. will order one with in the next couple days. but iam still looking for the sending unit if anyone knows the part number or an aftermarket that fits correctly.

 

[GA_Boater]

Does the gauge have any maker's mark on it? The sender and gauge may need to be the same brand.

Is the current sender mounted by one of the bolts securing the cylinder block cover?

 

[Ryche]

I will take a look at the gauge.. thank you for the reply.. the old sending unit basically screws in like a normal npt sending unit. has its own spot on the cylinder cover near the spark plugs.

Also have been looking hard at pressure gauges. can anyone recommend the correct one for my motor. do i just T off on one of the rubber hoses or do i buy an adapter and install it somewhere on the block.. this motor didnt come with a pressure gauge so this is something i'd be adding aftermarket. are there any other 650 owners who have installed a pressure guage via the block/head method.?