Evinrude Fuel Pump question

[PensacolaJason]

I'm at the end of my rope with my motor issue. Every other outing it seems to run fine, but on those outings where is doesn't it stalls out after idling for a few minutes and as soon as I give it gas it dies. I'm pretty confident that it is a fuel pump issue because the motor seems to idle back up when i pump the primer bulb, which goes soft pretty frequently. I've also checked compression and it's 145 on all cylinders. I also have great spark on each as well.

I currently have the oil side of my VRO disabled and premix at 50:1. I am looking to convert to a fuel-only pump. I have done a bit of research and I have come across two different kinds of pumps that say they are for my motor. One seems to be two pumps in one and the other is a straight single fuel pump. Any guidance on which i should get would be great. My motor is a E130TLEDM.

Single fuel pump replacement - https://www.offshoremarineparts.com/62-13-024.html

Double fuel pump replacement - https://www.ebay.com/itm/FUEL-PUMP-...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

 

[racerone]

Fuel pumps are driven by a positive pressure pulse from the crankcase.---And a slight negative pulse from crankcase.-------So have you checked for crankcase compression issues , yes or no ?----And have you inspected the internals of the fuel pump you have now , yes or no?

 

[PensacolaJason]

I rebuilt the pump with a new omc kit and re-ran all new fuel lines everywhere and checked all connections. My mechanic told me he doesn’t like to rebuild these VRO fuel pumps because they never seem to seal back up the way they need to. He recommended moving to a fuel-only pump. My motor compression is great, is that different than crankcase compression?

I feel like I’ve troubleshot just about everything and fuel delivery seems to be what it always comes back to. I’ve also read something about pulse limiters possibly causing this, but it sounds like that is almost never the case.

 

[racerone]

Crankcase compression is different from cylinder compression !!----It seems to be one of the concepts that is often mis-understood and mis diagnosed.-----Get your mechanic to help you.-----Not sure why anyone would say that VRO pumps are difficult to seal up.----They are so simple in my opinion !----And do you know the purpose of the pulse limiter , yes or no ?

 

[PensacolaJason]

I tried to find info on the pulse limiter. From what I gathered it seems to just keep flame from reaching the fuel pump. Info on it was very hard to find.

 

[racerone]

The pulse limiter is a flow fuse and is a safety item for the VRO pump !------Spend some time on ----Google----- to learn about flow fuses in fluid systems bot gases and liquids.------Do you understand that your motor is basically 4 separate motors with a common crankshaft and block, yes or no ?.------Each cylinder behaves separated from the cylinder next to it as far as processing the air is concerned.-----There are sealing rings on the crankshaft.

 

[PensacolaJason]

I will definitely do more research on flow fuses. I know some basics about 2-strokes, but I’m limited in my knowledge and have a lot to learn. Learning more everyday.

Here is is a video of what’s happening. I can get it to idle okay, although eventually the motor will die and the primer bulb will go soft. If I try and give it any throttle it dies almost immediately, as seen in the video.

https://youtu.be/c0RzXyvCY9Q

 

[racerone]

If you suspect that the " pulse limiter " is plugged then remove it .----Install a straight thru fitting .---Test run that way.-----Have you test run with a " known to be good " portable fuel tank and hose, yes or no ?

 

[PensacolaJason]

Yes, I ran it on a reliable portable tank setup I have with fresh gas, same issues.

 

[Crosbyman]

strange video ...... almost looks like you are killing the ignition….instantly

have you looked closely at wiring anything rubbing frayed grounding out ???

 

[racerone]

Opening throttle without advancing ignition also does NOT WORK.-----Yes there is much to learn about these wonderful 2 strokes.

 

[oldboat1]

In your U-Tube, it appears you are opening the carb throttle plates without advancing the timing -- engine would flood. As it's doing something similar when underway, it might make sense to be sure the carb openings are synced with the timing advance.

 

[racerone]

Are you sure that opening throttle like that causes " flooding " on a 2 stroke engine ?

 

[oldboat1]

Socratic method isn't real effective here, Racer. Explain what may cause the stall.

 

[PensacolaJason]

The same thing happens when I am up at the console giving it throttle, whether in gear or not. I was trying to get closer to the engine to get video and give it some throttle. Ive done this a hundred times and never had any motor stall.

I recently had had the carbs cleaned and a link and sync done as this motor is new to this boat.

 

[racerone]

??---Carburetor is supplying fuel via idle circuit.------Suddenly you open carburetor and remove idle circuit conditions.------So where would fuel come from ??

 

[PensacolaJason]

strange video ...... almost looks like you are killing the ignition….instantly

have you looked closely at wiring anything rubbing frayed grounding out ???

The boat was newly wired from bow to stern with a new ignition, so I doubt there is any wiring issues. I’ve gone through the entire ignition and wiring and haven’t seen anything unusual.

 

[PensacolaJason]

Something I am curious about. I pump up the fuel system and the carb bowls should be filled, then I start the motor and it idles fine. I would think that there should still be enough gas in the bowls to give it some throttle before dying if it is in fact a fuel delivery issue.

Would a bad fuel pump cause immediate stalling as soon as throttle is given like this? I would think it would have throttle for a bit and then die off after the fuel runs out or am I underestimating how much fuel and fuel pressure is needed to even give it a little throttle?

 

[racerone]

Something has to pull the fuel out of the float bowls.-------Vacuum / low pressure caused by a closed throttle plate .----OR airflow through the venturi when throttle plate is open.

 

[PensacolaJason]

??---Carburetor is supplying fuel via idle circuit.------Suddenly you open carburetor and remove idle circuit conditions.------So where would fuel come from ??

Main jet and high speed jet.