'93 vro question

[smorris]

I have twin '93 175hp 60 degree Evinrudes. I first mounted the motors and ran them with the oil injection hooked up. All seemed to run fine. Scared of the oil pump condition and not knowing the true history of the motors I descided to go premix.

Plugged the oil intakes and unhooked the low oil wires.

Port engine runs great.

Starboard will not idle, sometimes will run good after the boat planes but basically runs like crap.

Hooked vro on starboard engine back up, put motor on water hose and it ran idled for 15 min. without stopping.

Have not water tested, but I am confident this performance issue is related to the pump.

Hooking up both vro's would not be a problem except for the 60 gallons of premix in the tank. If the vro's will hold up.

Questions:
1. Is this the proper proceedure for bypassing the vro on this motor?
2. Is this an indication of a faulty pump in some way?
3. Do I need to buy fuel only pumps?

Thanks for any help

 

[tashasdaddy]

Re: '93 vro question

you need to disconnect the alarm wire on the oil tank, and the oil side of the fuel pump. if you want to try the oil side, you can reconnect, mark the level on the oil tank, run premix in the fuel tank, just in case, the extra oil will not hurt. then calculate how much oil you use, to fuel. if it is correct the pump is working. do you have separate oil tanks for motors?

 

[smorris]

Re: '93 vro question

I did disconnect the low oil wires, and plugged the oil intake side of the pump.
This is when the motor began running bad. When it was on premix.

When I hooked the oil back up it seems to run fine.

Have seperate oil tanks.

 

[Brew2]

Re: '93 vro question

Possibly one of the oil intakes you plugged was still sucking some air?? Might explain why it seemed to fix itself when you hooked the oil system back up.

Good luck!

 

[ezeke]

Re: '93 vro question

I think TD was saying that you need to disconnect the rest of the electronics on the fuel pumps; the four wire harnesses that run from the pumps to the main harnesses needs to be disconnected and taped off when running premix.

You still want to have the vacuum switches connected though, to let you know if you have a fuel obstruction on the premix side.

 

[smorris]

Re: '93 vro question

O.K. thanks, I will try that.

 

[smorris]

Re: '93 vro question

I looked and have one, 4 wire harness with the following wires
-purple
-black
-brown
-grey

Is this the wires to unplug? If so, does unplugging that harness, unpluging the low oil wires and plugging the oil line complete my job.

Thanks for the help, hope its not a stupid question.

 

[ezeke]

Re: '93 vro question

Tan, Black, Gray, Purple is correct. Tape the amphenol fittings off to keep them clean so that they can be reused at a later time.

There should be one lone tan wire running from the vacuum switch that you leave connected. That will have a separate bullet connector.

Check everything again for air leaks and you should be OK.

BTW, Be sure to plug the oil side of the fuel pump at the pump.