OPSS Switch question

[Jimmy]

Greetings - a couple questions as I upgrade to a electric fuel pump (working with the MM conversion kit)

1) the brass plug I need to remove to install the OPSS is giving me grief. Instead of fighting this any longer, I got a bright idea.....wondering if I can add the OPSS to the same outlet as the Oil Pressure sending unit. To avoid any extreme torque on that location, I would use a “AN” fitting, and remotely mound the sending unit and OPSS. Any reason this won’t work?

2) I am adding a fuel shutoff solenoid. Any reason I can’t power this off the coil “+” terminal ? Turn off the engine, solenoid closes. This is over and above the valve on top of the tank.

As always, I value, and appreciate the input of this group.

Cheers
Jimmy

[thatch]

Jimmy, I have made a similar change and it is perfectly acceptable. Mine is made up using AN fittings and stainless braid hose. In my case I'm feeding four units, the OPSS, two oil pressure gauges and a Cole Hersee low oil pressure alarm.
Tom

[ndutton]

1) That's how mine is, oil pressure actuated sender/switches mounted on a bulkhead, connected to the engine with 300psi oil rated hose. Be sure to run a ground wire to the sender array, the oil pressure gauge won't work without it.

2) Yes, you can power the solenoid shutoff from coil + with this advisement: to do it right, as you add load to the ignition circuit (this valve and the new electric fuel pump) you should measure the voltage at all components on the circuit. You don't want voltages lower than 3% of the source which for the engine circuit is the alternator. Voltage measurements below 3% indicate the entire ignition wiring circuit needs bigger wire. We have a voltage drop calculator on the USCG/ABYC Standards forum category.

[Jimmy]

One more question...

Thanks for the feedback guys. Last piece to this mini refit, is to relocate the coil, on a bulkhead. Like the idea of cooler ‘smoother environment. In doing so, I will need to increase ( replace with longer )the length of the coil wire that runs between coil and distributer cap. Any pit falls?

Again, Tnx

Cheers
Jimmy

[ndutton]

No pit falls with coil relocation, rock on. It would be interesting to get some IR temp readings of the coil before and after relocation to compare.

[Jimmy]

Future coil temp comparison

Thanks for the info.....
I will prep the A4 for a coil relocation, but not actually move it until after launch, around last week of April. I have a IR temp gun, so readings should be very accurate.

Cheers
Jimmy

[ndutton]

Great! Please mark a target on the coil so you are reading the same spot.

[Al Schober]

I've done the remote mount of the pressure sender and the OPSS. I used an 18" length of hose meant for a grease gun (Home Depot stock). Don't forget to run a ground lead to the block.
I also tried the solenoid fuel shutoff, but wasn't comfortable with it and changed it out for a ball valve. Perhaps if I'd had the fuel pressure gauge at the carb inlet (which I now have), I would have kept the solenoid valve.

[sastanley]

+1 on coil relocate working OK. I found a semi-custom wire available at my local NAPA. The high tension wire ended up being about 6" longer than A4 OEM to reach the bulkhead where I mounted the coil.

Look forward to your readings, Jimmy!

[Jimmy]

What’s ‘normal” fuel pressure/

Couple weeks later than planned, but finally splashed today. Will relocate coil after more seasonal temps set in.....single digits temps today- yuck

I noticed my fuel pressure gauge was reading a steady 2.5 lbs. ( just started running with a electric fuel pump)

Last year with the mechanical pump, I constantly showed 5-6 psi, on the same gauge.

What’s “normal ‘ fuel pressure? What would you consider “low’” fuel pressure?

Thanks for any pearls of wisdom you can share

[Dave Neptune]

Jimmy, about all the A-4 needs is 1 1/2 PSI, 2.5 is great and 5~6 is on the hi side and nothing to be concerned with.

Dave Neptune

[joe_db]

Couple weeks later than planned, but finally splashed today. Will relocate coil after more seasonal temps set in.....single digits temps today- yuck

I noticed my fuel pressure gauge was reading a steady 2.5 lbs. ( just started running with a electric fuel pump)

Last year with the mechanical pump, I constantly showed 5-6 psi, on the same gauge.

What’s “normal ‘ fuel pressure? What would you consider “low’” fuel pressure?

Thanks for any pearls of wisdom you can share

Electric fuel pumps come in different flavors. Some are 4 PSI, some are 2, some are 8, etc.
The A4 really doesn't care, 1 PSI will run it fine and so will 6. 8 might be pushing things.

[tenders]

Will relocate coil after more seasonal temps set in.....single digits temps today- yuck

This made me wonder where in the Arctic you might be rocking that A4 until I realized...CENTIGRADE. Still cold, but...Canada.

Canada...the home of the elusive Atomic Four "Stevedore" edition! Have you got one? Limited HP version of the A4 to comply with a short-lived Canadian trade restriction.

http://www.moyermarineforum.com/forums/showthread.php?t=162

[Marty Levenson]

What is "AN"

"1) the brass plug I need to remove to install the OPSS is giving me grief. Instead of fighting this any longer, I got a bright idea.....wondering if I can add the OPSS to the same outlet as the Oil Pressure sending unit. To avoid any extreme torque on that location, I would use a “AN” fitting, and remotely mound the sending unit and OPSS. Any reason this won’t work?"

Thanks! My ignorance is boundless.

[Marty Levenson]

Coil on bulkhead

When I moved our coil to the bulkhead I attached it with a chunky piece of aluminum as a heatsink. Didn't have an IR temp gun at the times, so no comparison available...