OMC fuel pump questions.

[shadowman]

I just rebuilt a 115 V-4 omc and removed the VRO system. This was a Nitro package deal and I think the rig is an early 90 model. I pulled a old pump from a 85 that uses the block port for a pulse, rebuilt it and used it on the 115. Break in went well, but now that Im running it harder the motor will surge at WOT. I can push the choke and it will run fine for about a 1000' and surge again. It seems the pump I installed will not meet the fuel requirement of the engine, or I have a restriction elsewhere. What fuel pump should I be using to replace the VRO pump on a 115?

Thanks in advance.:)

[BenKeith]

They make an Non VRO direct replacement for the VRO pump. Looks just like the VRO pump but witout the wires and oil lines and you use your VRO pump mounting bracket to mount it. The last one of those I bought list for $165, not sure what they go for now. You can buy those aftermarket or you can get them from the dealer.

[shadowman]

Is something different about the carbs on a VRO engine that cant use a standard OMC pump?

Thanks for the reply Ben.

[BenKeith]

I think the pump just has to put out between 5 and 6 psi and probably about 30 gph. Not sure what the actual volume rate is but figure if the motor burns 22 gph, you would want a little cushion.

[gotboostedvr6]

is there a way to disable the vro and keep everything intact?

[bigbore]

Do-it,thats what's up,just haft to pre-mix,n mount the pump(as-low-or-lower than the gas tank)n migtht wanna regulate it at 5pds.,at idle 7pds. is tough,it'll do it but questionable,n o.m.c.'s are reliable to high hell,so insteade of re-placing seat's n needles,re-gulate it.

[BenKeith]

If the VRO pump is already 10 years old, I wouldn't trust it as a fuel pump but yes, just unplug the the wire connector going to it and the two pin connector going to the tank so they don't set the alarm off is all thats required to disconnect oil injection on the JohnnyRudes.

5 - 6 psi it what a good OEM factory pump put out, don't know why you would need to regulate it. 7 psi might try blowing by the seats if the float level is a little high, but even regulated, you need to run 5.5 psi.

[shadowman]

After rebuilding two different pumps twice, I pulled the carbs and had a look. All was perfectly clean.... until I pulled the last screw out of the bottom float bowl and found a partially clogged main. Looked like a peice of gasket or fuel line just large enough to lodge itself in there. The carbs had been cleaned well when I rebuilt it and I felt the pump was suspect do to changing it over from VRO. Runs like a top now.:)

Thanks