Gas getting into crankcase 520H

[mclaugh417 2]

Hello all,

 

Winter is coming and im trying to get my 520H running again so I can use it to snowblow the driveway. It has sat idle for a bit now, and earlier this spring I tried to get it up and running. Had an electrical gremlin, but I got that squared away. Also fuel pump seemed to not be working right so I ended up putting a new one on (still vacuum style not electric). I just went to start it and the gas had fallen back towards the tank. Cranked it over for a bit and gas got into the fuel pump (I could see because the fuel line is clear on this one for some reason)  but it would not get to the filter after the pump. So the fuel must be entering the engine through the vacuum tube on the back of the pump right?

 

I mean I think that much is obvious, but just wanted to see if anyone else has had this problem before and what steps to take to fine the source of the problem.

 

Thank you all!!

[pfrederi 18,870]

[ri702bill 9,892]

Paul's picture is worth the thousand words. Short version - low pressure electric fuel pump.

 

My 2 cents. Pull the dipstick, check it for raw gas mixed in wirh the oil. If it is, do not attempt to start it. Drain the oil, fix / replace the fuel pump. Refill with fresh oil.

Edited 18 hours ago by ri702bill

[kpinnc 15,367]

I agree with the electric low pressure fuel pump modification. I've added this to every build I've done for several years and they are awesome. 

 

One thing to consider: as @ri702bill said, verify whether or not your oil is or is not contaminated. If you don't find gas in the oil, it may have simply drained back into the tank. This is a common issue on tractors that have the fuel tank under the seat. The smallest air leak in the fuel system will allow the fuel to drip back to the tank in just a day or two. If yours is doing the same, and you don't want to install the electric pump, you can add an inline primer bulb. This is also an exceptionally effective modification. Quick starts, which saves your starter, battery, and mental health. 

[ri702bill 9,892]

Oh, yeah.... Welcome!

[953 nut 61,681]

All of my workers and customs have electric fuel pumps, the only way to go in my opinion. Mount the pump lower than the tank and use the power going to your hour meter since it is fuse protected and turns off with the key.

[Ed Kennell 42,815]

All my tractors that have the fuel tank under the seat have a squeeze bulb to prime the fuel pump.    If the fuel pumps show any sign of failing I replace the pump and primer bulb with an e pump.

[mclaugh417 2]

4 hours ago, ri702bill said:

Paul's picture is worth the thousand words. Short version - low pressure electric fuel pump.

 

My 2 cents. Pull the dipstick, check it for raw gas mixed in wirh the oil. If it is, do not attempt to start it. Drain the oil, fix / replace the fuel pump. Refill with fresh oil.

It certainly had the smell of raw gas in it. Unfortunately, I just changed the oil lol. 

 

Thanks for the info!

[mclaugh417 2]

3 hours ago, kpinnc said:

I agree with the electric low pressure fuel pump modification. I've added this to every build I've done for several years and they are awesome. 

 

One thing to consider: as @ri702bill said, verify whether or not your oil is or is not contaminated. If you don't find gas in the oil, it may have simply drained back into the tank. This is a common issue on tractors that have the fuel tank under the seat. The smallest air leak in the fuel system will allow the fuel to drip back to the tank in just a day or two. If yours is doing the same, and you don't want to install the electric pump, you can add an inline primer bulb. This is also an exceptionally effective modification. Quick starts, which saves your starter, battery, and mental health. 

Yeah, the mental health is a big portion haha. Dont want to be thinking about this thing while im at work but my primitive brain is making me! Im going to investigate the electronic fuel pump route, but I feel like a primer bulb would work just fine, and while im at it just change all fuel lines/clamps to eliminate air leakage.

[mclaugh417 2]

1 hour ago, 953 nut said:

All of my workers and customs have electric fuel pumps, the only way to go in my opinion. Mount the pump lower than the tank and use the power going to your hour meter since it is fuse protected and turns off with the key.

That was my biggest worry with going to electric was figuring out where to wire it. Thanks for letting me know about the hour meter detail!! Do most of those electric pumps just have 2 wires? positive and ground? If so, it doesnt sound so difficult after all other than mounting it I guess. Do you have a certain place you like to mount it? I know lower than the tank, but didnt know if through trial and error you have found something that works best? 

[kpinnc 15,367]

2 minutes ago, mclaugh417 said:

but I feel like a primer bulb would work just fine, and while im at it just change all fuel lines/clamps to eliminate air leakage.

 

I agree 100%.

 

The most common place I can think of for air to get in the lines is the fuel pump. If for no other reason the big temperature swings being so close to the engine. My 520-H still has a primer bulb and it worked great. 

 

Still say the electric pump is awesome, but it does tax the electrical more than anything else. 

[mclaugh417 2]

56 minutes ago, Ed Kennell said:

All my tractors that have the fuel tank under the seat have a squeeze bulb to prime the fuel pump.    If the fuel pumps show any sign of failing I replace the pump and primer bulb with an e pump.

Thanks for the reply Ed. Thats a good point. My fuel pump had signs of failing and I tried the amazon special traditional fuel pump, and I think it is even worse than what I had to begin with. A primer might make it work right but with the aftermarket garbage I tried probably best to just bite the bullet and go e pump

[mclaugh417 2]

4 minutes ago, kpinnc said:

 

I agree 100%.

 

The most common place I can think of for air to get in the lines is the fuel pump. If for no other reason the big temperature swings being so close to the engine. My 520-H still has a primer bulb and it worked great. 

 

Still say the electric pump is awesome, but it does tax the electrical more than anything else. 

Yes, I dont think its a mystery that these 520s run on the hotter side as well. To that point about air leakage at the fuel pump, I had a pump on there but it was slow to fill the filter so I replaced it with a amazon one. Looks identical....but. We all know the rest of the story there. Maybe that one just sucks and I should not cheap out I guess (as well as change hoses haha). Lesson learned.

 

Did you mount the primer bulb just below the fuel pump?

 

One other question regarding this, would the primer bulb help the fact that the gas got into the crankcase without even getting to the fuel filter (right after the pump)? Because I know the gas at least got to the pump...but no further. 

[kpinnc 15,367]

6 minutes ago, mclaugh417 said:

Did you mount the primer bulb just below the fuel pump?

 

One other question regarding this, would the primer bulb help the fact that the gas got into the crankcase without even getting to the fuel filter (right after the pump)? Because I know the gas at least got to the pump...but no further. 

 

Yes, bulb mounted a few inches below the pump. Just out of the way of the left pedal travel. 

 

If your fuel pump is leaking through the crankcase "pulse" line, it should be replaced regardless. Otherwise you'll destroy the engine. 

[Bill D 2,343]

You could use a Kawasaki pump and mounting bracket.   A little ugly, but a good quality pump that's made in Japan.  Use Kawasaki pump# 49040-0803.   The pulse line  location is different than the pump in the video.  Better configuration for this application. 

Edited 15 hours ago by Bill D

[ri702bill 9,892]

7 hours ago, kpinnc said:

 

Yes, bulb mounted a few inches below the pump. Just out of the way of the left pedal travel. 

I added a primer bulb to my C81 to aid in starting when the tractor was inactive for a few weeks. I got a tad creative to mount in below th tank, as I have seen too many sketchy applications where it was hanging out near the left pedal just waiting to get snagged on something. Made a cradle & spring return pusher activated under thr seat - flip up the seat, a couple of pushes, seat back down, start it up....

 

[Ed Kennell 42,815]

3 hours ago, ri702bill said:

I got a tad creative

Next generation...extend the plunger up to the seat so it squeezes the bulb when you hop on.    

[953 nut 61,681]

34 minutes ago, Ed Kennell said:

Next generation...extend the plunger up to the seat so it squeezes the bulb when you hop on.    

And if you are mowing over a rough area and bouncing up and down in the seat you don't even need a fuel pump, it would be but-bump activated.   

[953 nut 61,681]

11 hours ago, mclaugh417 said:

One other question regarding this, would the primer bulb help the fact that the gas got into the crankcase without even getting to the fuel filter (right after the pump)? Because I know the gas at least got to the pump...but no further. 

That is why I like electric fuel pumps, they are not connected to the crankcase of the engine with only a thin diaphragm standing between gasoline and your engine's oil. It doesn't matter what type mechanical or vacuum fuel pump you have, if the diaphragm leaks your engine's oil will become diluted and it could be catastrophic.

12 hours ago, kpinnc said:

the electric pump is awesome, but it does tax the electrical more than anything else. 

Unless you have a 3 Amp charging system and battery ignition there shouldn't be a problem. Most Wheel Horses have a 15 Amp system and the electric fuel pumps draw about 1 Amp.

[gwest_ca-(File Mod) 11,669]

If you get fuel pump power from the hourmeter make sure you connect to the + side of the gauge. Some models ground the hourmeter through a pressure switch. Not running = no oil pressure = no hours added the the gauge.

You can connect to the + side of any gauge.

You may be required to stop at the RUN position for a few seconds to build fuel pressure on a START. Most times the gauges are not powered on START.

[ri702bill 9,892]

4 hours ago, Ed Kennell said:

Next generation...extend the plunger up to the seat so it squeezes the bulb when you hop on.    

I actually considered frame mounting it under the left footrest, with the pusher activated from above via a non-connected actuator to allow easier foot rest removal. I was concerned it would be too low (and a lot more work!).