F300 Water Pressure Sensor

[Offshore 27]

Is a sealant such as thread tape recommended for the water pressure sensor to adapter connection? Also for the adapter to block connection?
The service manual makes no mention and only lists torque values.
Thanks

[boscoe99]

If the SM makes no mention of a sealant then sealant is not used.

A gasket is used to ensure a leak free connection between the adapter and the block.

I seem to recall that the sensor has an O ring which will seal the connection between the sensor and the adapter. Or maybe it uses pipe threads. Either case, no sealant.

[Offshore 27]

Thanks for the prompt reply. The threads are not tapered(NPT),and the sensor does have an O-ring.
I do question combining 3 different metals in an engine that will see saltwater use. Stainless steel(sensor), coated bronze(adapter), and aluminum(block).
Boat underwater running gear have this combo, but they use anodes for corrosion protection.
Lastly the 2mm opening for the adapter into the water jacket seems small considering the problems folks have just keeping pilot tube openings clear and they are twice the diameter.

[TownsendsFJR1300]

I would think regular flushing of the power head would help prevent clogging.

Re the pitot opening, most folks DON'T flush the lower unit pitot tube opening. With regular maintenance, the pitot tube clogging is a non-issue....


http://www.yamahaoutboardparts.com/f...g-th23159.html

[boscoe99]

Almost any design of any product can be questioned. It is all about trade offs. Compromises.

What is the old saying about getting quality, low pricing, speed of delivery? Pick any two. You can't have them all.