Any mechanics on board (***FIXED***)

[Shadslinger]

I'm trying to troubleshoot this boat problem before breaking down and taking it to a shop. I'm pretty mechanically inclined when it comes to vehicles but these outboards are a different animal. Boat is a sea pro sv2100 and motor is a Johnson 130hp ocean pro 2 stroke. Cranks and idles fine. Runs fine at WOT for a minute or two then starts cutting out and bogging down till it stalls if you don't let out of it. Primer bulb feels empty and you can pump it back up tight and take off WOT then same problem reappears. It is constant cycle. Definitely a fuel starvation problem.

Primer ball and hoses were replaced in the spring and fuel water separator is currently bypassed eliminating that as a problem. I pulled the fuel pickup and checked screen and anti siphon valve today. Both are clean and clear. Fuel pump going bad? Sucking air from somewhere else? Anybody had this problem before?

[rdnkjp]

Kinda sounds like the fuel pump may not be working properly. Also one thing you can check first is the fuel tank vent. Had an old boat years ago that had a portable plastic tank. Manual open vent valve. Forgot to open it one time and it acted the same as you are describing. The fuel pump could not pull fuel from the tank because there was no way for it to overcome the lack of air getting in the tank. Hope that makes sense and good luck.

[drag4striper]

Slinger there is a large thread about this problem on seaproboatowners.com.. If your gas cap has a vent check it out could be stopped up.  

[Shadslinger]

Thanks rdnkjp. I forgot to mention I've checked the vent as well. Mine vents through the gas cap. I ran a piece of weed eater string down that tube and found no restrictions. Also put my ear to the cap and you can hear it Sucking when you squeeze the ball. I'm really leaning toward fuel pump but that's a minimum $150 guess basically.

[Shadslinger]

Thanks drag4striper. We were posting at the same time. I'll check that out as well

[striperjohn]

I had a similar problem this spring and it was a leaky diaphram in a fuel pump.

[johnr]

What striperjohn said about the diaphragm is a good bet. I've had smaller outboards act the same way and replacing that diaphragm has fixed it.

Also, my new Yamaha wouldn't run unless the fuel cap was off earlier this year. It is also vented through the cap, which I thought looked all clear. I ended up replacing the cap itself and it fixed the problem. My primer bulb would be sucked totally flat though when this happened.

If your bulb isn't sucked flat, I'd say you are losing pressure from the engine or introducing air into the line.

[Shadslinger]

Mine has the VRO fuel pump. Tomorrow when I get home from work I'm gone pull it apart and check those diaphragms out. I was gonna do it this afternoon but time I wrestled with the fuel pickup and anti siphon Valve I didn't feel like digging deeper.

[mississipi]

You might want to check closely the hose. If it plugs up to motor unplug it and see if it pumps tight and holds. If it don't plug up pump the primer a good bit and look for a gas leak. If you have a filter, change it. Start it and while going down the lake have someone constantly pumping the bulb. If it runs ok then you may have a fuel pump issue. Replacing the VRO pump can be expensive. If you don't mind mixing your gas an electric pump can be installed in line for usually about 100 bucks that will work great and you never have to pump the bulb again. Good Luck!

[archenemy]

Hunter can you get your hands on a portable fuel tank ? This will tell you whether or not you need to look at the pump.

[seaduck]

Now my suzuki is a 4 stroke. I pulled the fuel pump off and squeezed my primer bulb to see if the fuel pump was leaking. I was good there. So I went to the high pressure filter and thats where my problem was. The gas lines had broken down under the cowling and pieces were clogging the high pressure filter. Replaced that and had no more problems at higher rpms. Like i said that was my 115 4 stroke. Fuel problems can be a complete pain but good luck!!

[Pete D.]

Slinger,

I have that exact same motor. Mine is an evinrude 130hp. I actually have an entire VRO pump laying around that has the oil side blocked off. It works fine. I had rebuilt the inside of the pump (diaphrams, check valves, o-rings) and was still having issues. Ended up being tank fitting, but I found that out AFTER I slapped another fuel pump on there. I put on a pre-mix back to back pump that I got off Ebay. The thing works great.

Of course, either of these methods will only work if you pre-mix. It certainly sounds like a fuel pump issue to me.

I have completely broken this motor down to the piston rings and crank bearings, and have put the whole thing back together. If you ever have any ?'s on it, I am sure that I can help you figure it out.

This is the pump I now use. Beats $300-350 for a new VRO, but I actually trust Premix over these VRO's. www.ebay.com/itm/Johnson-Evinrude-VRO-Replacement-pump-W-Ratio-Rite-Crossflow-Looper-90-250HP-/232097656188

If you tear the VRO down you can get rebuild kits for it as well, but it will cost you about what it costs for the VRO replacement pump (the one I sent you the link to).

If you want to try the one that I have to see if it fixes your issue hit me up on here. Peace!

[Pete D.]

And I agree with Arch, try another tank to rule out the boat side fuel supply.

[Shadslinger]

I had wanted to try a portable tank but my tank out of my old boat has quick connect fittings. I rigged it up and pumped the ball and could hear air at the quick connect. Figured it won't no need going to the lake for it to suck air there on the portable and not tell me anything. That's when I decided to check fuel pick up and ASV. Both look good. Hoses and ball are 6 months old. Fuel/water separator bypassed to eliminate that as a problem also. I pulled the VRO pump this evening and opened it up. Both diaphragms and o ring look brand new. No rips, tears, or deterioration anywhere. Everything was clean and clear also. Put it back on the boat and ran it on muffs to make sure it still cranks and runs after opening the pump up. I'm afraid I'm running out of options other than going ahead and taking it to a shop.

[Pete D.]

There can be small cracks in the fuel pump on the INLET side that will hide under load. Those older VRO's had plastic fittings that were pressed on and it was a big system flaw. There is a small rubber flap that is deep inside the VRO that is the biggest culprit to failure.

Here is a great test for you.

Go to lowes and get a variety of clear hose. Run a piece from your primer ball to the fuel pump. Then run a piece from the pump to the fuel manifold (the plastic piece that goes to the carbs.) Then zip tie your connections tight and look for air bubbles in the line. If you have air past the fuel pump, then there is an internal fault in the pump. This is the last thing that I would do before giving up if I were you. I bet you will have air in the clear line past the pump.