Guage wiring + fuel pressure on Johnson 300 V8

[Spajn]

Hi,

I just replaced my Suzuki DT200 with a Johnson/Evinrude 300 2 stroke V8. I was told that it was from 1990 but i suspect that it's a ´86.
Anyway, this engine has a separate electric fuelpump with adjustable fuel pressure. I'm getting around 1-2psi on the guage for fuel pressure.
How high pressure should I set the pump to? It's a standard engine with no other modifications. 8carb intake.

I use a standard OMC control for the engine and I'm just about to install some guages; A revcounter and a water temperature guage.
I can see that there are two senders mounted in the top end of the heads with a brown/tan cable running from each sender.
There is also one auxillary sender for temperature mounted on the port side head.
Do the two standard mounted senders hook up to the buzzer in the remote control? Or are they intended for hooking up with a temperature guage?

There is a outlet for three pins below the ignition key in the remote control. It seems like the three holes are +, ground, and one for something else? Is this for the tach pulse?

Please give me any tips of how to wire guages to this outboard. All other tips, experiences etc.. regarding this type of outboard are welcome.
Does any one have a wiring diagram?

I live in Sweden where this is not a very common outboard engine, so help is sometimes kind of hard to find.

With best regards

[Markus]

Since you are from Sweden, I will answer the questions I can answer, even though I have never owned an OMC. ;)


this engine has a separate electric fuelpump with adjustable fuel pressure. I'm getting around 1-2psi on the guage for fuel pressure.
How high pressure should I set the pump to?


On a carburated engine, pressure only matters if it is too high and unseats the valves in the float bowls. What matters is flow. At 1-2 psi you may well have enough flow, but 3-5 psi is more typical with the pumps I know of.



Do the two standard mounted senders hook up to the buzzer in the remote control? Or are they intended for hooking up with a temperature guage?


They are for the buzzer.

[Spajn]

OK, Thanks for the info Markus!

[Forkin' Crazy]

In reference to the plug on the control box, you can get the male plug from BRP. The purple wire is power, max 5 amps. The black is of course the ground, and the gray is the tach signal.

If you install a temp gauge, you will need to mount and wire in a sender. The two brown wires on the heads are for the temp horn. Unplug and ground them to test. Either wire should set off the horn.

Give me the model number and I can tell you what year it is.

:)

[Spajn]

Thanks alot, your info was really helpful. I'll get a new sender and temp guage in addition to the temperateure horn.
At the moment I've got the fuelpump hooked up to the purple wire so that it starts automatically when I turn the ignition on, I'm not sure if this is the correct way to connect it. I've read posts on this forum about so called fuel pump relays. What is a relay? What does it do?

The plate with the model number is pretty messed up so it's kind of hard to tell what is actually written on it. It looks like this; J300T?CO?.
However, I can see the engine number (the long number with only digits), can I use this to see which year the engine was manufactured?

[Spajn]

The tachometer:
Does anyone know how many "P" i should set the tach to? I think the tach is adjustable between 4 and 12 P.

[Markus]

What is a relay? What does it do?



Relay is relä in Swedish.

[Forkin' Crazy]

The only 300 in my book that has the following letter T is a 1985. That is 300TLCO and 300TXCO.

I believe the "P" on the tach is for "pulse" signal from the motor.

A relay is just an electronic controlled switch. Since the circuit of the purple wire is limited at 5 amps, I would recommend that you use one for the pump and use the amp fuse recommended by the manufacture. I used the purple wire to as a "switch" wire to my relays. The only thing it directly powers is the volt gauge and tach. I use the Bosch trim relays from BRP.

[Forkin' Crazy]

Relay is relbä in Swedish.

Where is that on my keyboard? ;)

[H2OPERF]

The engine has a 12 pole stator and it puts out 6 pulses per rev so depending on the tach brand p could mean poles or pulses,most of the ones over here u put on 6. but the one u have sounds like it should go on 12.

[Spajn]

Thanks guys. I installed a relay for the fuelpump yesterday with a separate fuse and it seems to work fine.
I'll try installing the Tach by trial and error testing it on both 6 and 12 P as soon as I get the motor back on. I had to remove the motor in order to replace the tilttube and do some paint jobs on the stern brackets and some other minor touch up's.