!50 HP Ocean Runner fuel pump

bassarama · #1 07-01-2010, 02:49 PM

Hello fellow fishers.

I've been having fuel problems running out of power while underway, I would pump the priming bulb and the motor would run fine again for another couple of minutes, then the same problem came back, on and on...

By the end of last year's season It got to the point that I could not idle without primming the bulb.
Unfortunately, for health reasons I was unnable to work on the boat yearly this Spring. Today I opened her up and checked everything related to fuel, the last check was the fuel pump.

Some of you have hinted me of a possible problematic fuel pump. I took it apart and inside the diaphram cup I found a broken O'ring as you can see.
Measuring the O'ring, I believe it fits and goes inside the center housing that accomodates the "shaft looking" part that is attached to the center of the diaphram which looks fine by the way. Is that "shaft lookin" thing suppose to be loose like this?

Now I asked you guys, is it possible that the broken O'ring is causing the fuel pump to get airbound causing fuel delivery problems ?

Thanks in advance guys!

Here's a pic:

THEFERMANATOR · #2 07-01-2010, 03:22 PM

Yes that piston is supposed to be loose like that, it is the oil piston. By that piston being loose is how it varies the oiling from idle to top end. As for the O-ring I can't help yeah there. I just tore a late model VRO pump apart and it has a plastic piston in it without an O-ring, but it is a VRO2 pump. Any obrstruction to that piston movement can cause issues with the pump though.

THEFERMANATOR · #3 07-01-2010, 03:29 PM

I just went and re-looked at your pic and I think I see your problem. That metal sleeve is supposed to stay inside of the plastic end cap, but appears as though the oil pump piston is frozen inside of the metal sleeve. Heres what it should look like in there. As you can see that metal sleeve that is on yours is pressed into the fuel pump end cap on mine. And the oil piston is just a plastic sleeve. It looks like the seal on the end of your oil piston has stuck inside the oil piston bore and is causing it to hang up the fuel pump. If your not running the VRO I would just get rid of that piston all together and make sure to block off the oil inlet and let it go.

bassarama · #4 07-01-2010, 04:01 PM

Thanks Fermanator

Indeed I removed the VRO 3 years ago when I bought the boat, It only starter to give me probems last Summer, the oil inlet to the VRO is plugged with a piece of hose and a SS bolt.

What you're saying makes sense...so the O'ring goes where? and how do I remove that little piston without breaking additional components?

THEFERMANATOR · #5 07-01-2010, 04:19 PM

You need to slide that metal portion off the piston. I would hold the metal portion and see if you can push the piston back through it and release it.

bassarama · #6 07-01-2010, 04:58 PM

Thanks again Fermanator

Went to the auto parts store and bought a replacement O'ring. The sleeve on my pump doesn't appear to be pressed in the end cap, it looks very smoth as in a new part. Its hard to tell by looking at the pics, however if the sleve was pressed in the cap originally, I believe the wall would be rough, true?

Here's a couple more pics:

Is it normal for fuel to leak thru the picton orifice when I prime the bulb? (bottom picture)

THEFERMANATOR · #7 07-01-2010, 10:28 PM

That sleeve needs to come off of there and be put back into the housing or else the pump will continue to bind up inside. That sleeve should be flush on the end, not recessed in.

bassarama · #8 07-02-2010, 09:11 AM

ThEFERMANATOR you're my hero

Thank you, thank you!

I re-read your posts and went back to the motor. As you suggested I held the sleeve with the pliers and pushed out the piston with a wood dowel, it took some force, that little sucker was stuck in there big time.

Here's the sleeve out:

If I understand you right, The sleeve is supposed to be mounted like this, right?

As you stated above, since I don't run the VRO I can remove the little oil plastic piston and get rid of my problem, should I remove the sleeve too?

Thanks you for your immensely for sharing your knowledge.

Joe

THEFERMANATOR · #9 07-02-2010, 12:01 PM

I would remove both of em and just make sure the oil end is blocked off and let her go. That metal sleeve wasn't ever meant to move in there and I'm sure that O-ring had the pump bound up internally. If that style pump can't go full travel both directions then it won't pump fuel at all. I'm willing to wager that ethanol caused the sealing ring on the end of the oil pump piston to swell and seize itself inside of the sleeve. Just one more reason I'm glad I have the fuel only pump.

bassarama · #10 07-02-2010, 12:42 PM

I removed both the sleeve and piston; installed everything else and fire her up...so far I have a reason to

it idle like a charm!

Next week I'll take her to a local lake for a test run, hopefully that little oil piston hasn't caused other damages on the fuel pump, you know behond the diaphram etc. do you think?

In a way I'm glad I'm not depending on the VRO for lubrication...that little system could easily caused a major engine failure.

Thanks

Joe