Re: CB650 SC Oil Cooler for CB750's

Posted by sgtslag on Apr 18, 2012; 5:06am
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/CB650-SC-Oil-Cooler-for-CB750-s-tp3909678p3919098.html

X's adapter is very similar to mine:  it has two ports on one side of the adapter, so you can install either a pressure sensor, or a temperature sensor.  Most gauges have a remote sensor; they are either electrical senders (resistance varies according to pressure/temperature, and gauge reads the resistance, translated into PSI/Degrees F), or mechanical, Bourdain Tubes, which translate the pressure/temperature into hydraulic pressure, which mechanically moves the needle on the gauge.

The electrical gauge requires a single wire, which you have to supply, between the sending unit, which screws into the hole in the adapter on the engine, next to the radiator hose (the mechanical sensor screws in, also).  The Bourdain Tube needs to be run up to the gauge, without bending/kinking it, which destroys the whole gauge unit.  The mechanical gauges typically have a 270-degree needle deflection (typically 4% accuracy, in their specs. -- only requires power for the backlight, if you need it); the electrical gauges typically have a 90-degree needle deflection, but the same range of temperature/pressure, so much less accurate to read, and they require good electrical connections to function.  They both will work, it is just a matter of preference.

Sunpro gauges (which is what I use) come with the adapters needed, to fit into the holes on the adapter.  Don't know if other brands include the adapters, or not.  Cheers!