Going from VRO to premix?

[Jayboid]

I have a 1989 Johnson 150hp VRO on a 21' walk-around which needs a new fuel pump. I'm thinking this might be a good time to go to premix. My replacement VRO pump is #5007420 and the no oil premix pump is part # 5007422. I expect that the premix replacement pump will be an easy install using the same mounts, but the bad news is that the premix pump is still very very expensive compared to other gas-only pumps. I don't suppose that Johnson has mounts on this engine for the cheaper pumps. If not, would it be possible for me to adapt one to fit, by connecting a tube to the vacuum pulse outlet and connecting up the 2 gas lines? Will this vacuum line be enough to run a standard or aftermarket pump? If so, do you have a Sierra or other fuel pump to suggest. I should be able to fabricate a mount for it . Or would you just advise me to bite the bullet and order the #5007422 premix pump... I've seen it available for $225 plus shipping.

 

[kenmyfam]

Re: Going from VRO to premix?

Check this thread out. There are many others to review as well.

http://forums.iboats.com/showthread.php?t=265363

 

[Jayboid]

Re: Going from VRO to premix?

Thanks for the info. I've read several of the threads so far and have many more to go. A couple of threads pointed out that the vro pump and its expensive premix look-alike is a more powerfull pump than a standard pulse pump, and that it should be replaced by two standard pulse pumps! I don't think I'll do that. But does anyone know of a standard pulse pump that is big enough to supply a 150 hp and costs a whole lot less than $225?

 

[ezeke]

Re: Going from VRO to premix?

Is your existing pump functional at all?

If not, you could repair the gasoline side with a kit and use it as a premix pump for less than $100. US.

If it is functional, block the oil side and run it as a premix pump until it dies for $0. US.

 

[kenmyfam]

Re: Going from VRO to premix?

Aftermarket premix for mine was $56
OMC premix was $72 I went with this one.
Gas and oil mix pump was $508
That was for a 140hp V4 1985 model.

 

[ezeke]

Re: Going from VRO to premix?

Even in the 1970's, OMC recognized that one lift pump was not adequate for three two barrel carburetors. Two lift pumps were always used on the V6 motors to avoid the risk of running lean and ruining the motors.