Oil Pressure Gauge

[jayski81]

The oil pressure guage on my 1977 vintage Atomic IV flips to maximum immediately upon engine start-up. The boat is new to me and the mechanic gave the engine a clean bill of health in the pre-sale inspection. I'm guessing that the pressure is fine but the sensor is faulty. Any suggestions on how to proceed? We are out of the water for the season and I do not want to go into next season without addressing this issue.

[Don Moyer]

Each manufacturer of gauges tends to match their gauges to their own sending units. Therefore there are variations between manufacturers in terms of what happens to make a gauge flick to either a full right or a full left indication, but in general, a full movement one way or the other would indicate that the wire from the sending unit is either shorted to ground, or open.

In either case, the first thing I would do would be to check the sending circuit very carefully. If the wire disappears into a wiring harness, or is otherwise not visible much of the way to the cockpit, you might run a temporary wire between the sender and the gauge. If the gauge then operates normally, you will know that you'll have to troubleshoot the original wire further, or replace it permanently.

[Fred]

Don, is there another way to check oil pressure in the event of a faulty gauge?

Is there somewhere on th engine to attach a temporary oil pressue gauge?

thanks

[randall]

There is a slotted plug directly behind the carb (late model) on mine. I busted the threads on the regular spot where the pressure sender goes... Don told me this spot was just as good.

I used a 6" high pressure rubber line, and put my sender on that.

It took an impact driver to get the plug out, and THAT was kinda' scary to be banging on the side of the block.

My oil pressure gauge is nice and steady.

So take the carb off, and you'll see the location you're looking for.

[Fred]

Thanks, we'll take a look at it.

Fred