520H Fuel pump

[formariz 11,988]

Decided to change 520's fuel pump to an electric Facett. I recently replaced stock one with a new one and it works fine.However when blowing the 8 inches of hard snow going up my neighbors really steep driveway, tractor started surging  in the middle of hill. Going downhill and level never an issue. Pretty sure that it was getting starved for fuel in the big incline. Blower load and steep incline just too much for stock pump to pull fuel from the low placed tank.

[gwest_ca-(File Mod) 11,102]

Pump mounted below the fuel tank? They push fuel much better than pulling it.

If you have the line off at the tank see if gravity will drain the tank with a steady uninterrupted flow. The screen in the tank may be restricted.

 

Garry

[formariz 11,988]

Checked that already and it flows fast and easy. Screen is totally clear. Vacuum pump just not enough in that extreme condition. Electric pump will be mounted right under tank.

[lynnmor 7,354]

Did you use one of the cheap pumps like found on eBay to replace the stock one?  I have never had an issue with the stock Onan pump no matter how hard it was worked.

[formariz 11,988]

4 minutes ago, lynnmor said:

Did you use one of the cheap pumps like found on eBay to replace the stock one?  I have never had an issue with the stock Onan pump no matter how hard it was worked.

No. Pump was a more expensive one from the Onan parts place. This driveway is a very steep incline probably about 30 degrees for most of it. That coupled with the 7 to 8 inches of icy wet snow really put a load on tractor. Again, tractor never surges in any other condition or time, not even towing a trailer with over one ton of gravel in it.

[WildmanC120 613]

Maybe your float level is off. 

[formariz 11,988]

38 minutes ago, WildmanC120 said:

Maybe your float level is off. 

Went up same driveway today with no snow and blower off no problem. Tried it again with blower on, again no problem. I am convinced that with all that load in addition to the incline tractor was just not getting enough fuel.

[Lee1977 6,804]

The best thing I did to my 520 was an electric fuel pump.  It was a bear to start with the stock pump. I broke it changing the fuel line. Put on an electric pump. Now when I start it I turn the switch on let the pump hit 3 or 4 times turn to start pull up the choke and right back down and it's running.

[dclarke 4,034]

I put an electric pump on mine, it sure starts easier. 

[lynnmor 7,354]

2 hours ago, dclarke said:

I put an electric pump on mine, it sure starts easier. 

That mounting is not an option if there is a rear lift.  I would like to see how others mounted an electric pump that will not interfere with anything.

[dclarke 4,034]

39 minutes ago, lynnmor said:

That mounting is not an option if there is a rear lift.  I would like to see how others mounted an electric pump that will not interfere with anything.

That’s true, I took the rock shaft out since this is my dedicated snow machine. 

[WildmanC120 613]

17 hours ago, formariz said:

Went up same driveway today with no snow and blower off no problem. Tried it again with blower on, again no problem. I am convinced that with all that load in addition to the incline tractor was just not getting enough fuel.

 

Well if you are loading it then yes you will be burning more fuel. Unloaded the float hight probably won't make a difference. 

 

I still suggest to check this as the stock pump should be more than enough to feed the engine loaded and unloaded.