520H 20hp Onan issues

[HueyR9 8]

Hello everyone, I need help troubleshooting my 520H 20hp Onan engine.  I have replaced the fuel pump, fuel filter, and fuel lines from the pump to the carburetor.   Last night I soaked the carburetor in cleaner overnight and just got everything put back together.  The following issue still persists:

 

Starting is fine and sounds like it is running great.  Driving it around the yard it does fine everywhere from low to full throttle.  When I engage the mower deck, it still continues to run fine going forward and transitioning into reverse.  However, when I am in reverse and transitioning to neutral, still with the blades engaged, the engine sputters out.

 

Thinking through my limited knowledge of engines, it seems to be an issue of not getting enough fuel or air but I do not understand why it would only be a problem from reverse to neutral.

 

Thank you for any information provided.

[lynnmor 7,822]

If it is fuel related, the float may be faulty or not adjusted correctly.

 

My guess is that it is ignition loss due to safety switches, bypass the seat switch to test it.  Then check the switch for the gear shift under the plate that is vertical.

[8ntruck 7,835]

 

I agree. It sounds like a safety switch somewhere.  I'm not familiar with the 520's, so I can't elaborate any further.

 

My 14-8 no name tricks me occasionally with its PTO safety switch.  Goes from running fine into a crank but no fire mode.  I don't always remember to check the PTO safety before starting to trouble shoot other areas.

[Tuneup 1,452]

I've got the 516H on the road and am working on the bugs. There is the over-active governor but the really funky issue is the stall. Only happens when warm and on a lean to the left. Not fuel related and I bypassed the switches (not that there are any) and ran the coil to the battery. Indicates the nice clean trigger is at fault but.... on a lean to the right only? You might want to pull the (+) coil wires sans the capacitor, wire it to the battery and see if it goes away. That'll rule-out the trigger and coil at least. Heck, I've got the day off so I get to play with Wheel Horses!