416-8 stalls

[Watch this Richard 9]

Pretty sure this has happened to others.  If there's a good thread - please just point me to it.  

 

I have a 1997 416-8 that I picked up from a barn.  It's been a lot of work ---- but it's up and running. 

 

I used the tractor to cut the entire property (1.5 acres) twice ------ and out-of-the-blue, 

it starts to stall.  Starts if I let it sit.  Clue - my property is almost entirely on a hill  (West by Gawd). 

Fuel is a possible culprit. 

 

 During restoration, I replaced plugs, voltage rectifier, air filter, and fuel filter.  Just bought 10' of fuel line 

at Rural King ---- will try that.   B+ line reads a steady 14V ----- except when it stalls (naturally).  

I'll also change oil, since oil and oil filter, since pressure has been a problem, before.  (shut down when I forgot to 

twist cap on all the way).  

 

Figure it's either ignition or fuel (duh.....) ---- but wondering best way to figure out which.  

 

I shake the fuel line, and it starts some times.  There a small amount of fuel visible in the filter. 

(looks half full  --- but I suspect that's normal).  

 

I noticed a hose on the back of the fuel pump.  Not sure where it leads  ----  but there was a lot of dirt caked around that hose.  

I disassembled pump --- everything looks fine.  The spring is a BEAR to re-install!   

 

I really want to get this machine working ------ the mower deck leaves a beautiful, almost perfect trim.   

 

 

Edited August 6, 2018 by Watch this Richard

[pfrederi 17,143]

I am not an Onan guy but the third hose is what brings the crankcase air pressure changes to the diaphragm in the fuel pump.    Have you checked the float level in the carb.  (I know the Kohler setting but not the Onan)

[lynnmor 6,764]

A quick and dirty way to check for a fuel problem is to dump about a teaspoonful of gas down the carburetor throat and immediately attempt to start.  If it fires for a bit, you have a fuel problem.  A quick and dirty way to check ignition is to open the gap on and old plug to about .040", connect it to a plug wire and ground the body of the plug against the engine.  Run the starter and watch for spark.

 

The engine manual will give you direction on how to troubleshoot the ignition. manual

 

I recently had heat related ignition failures and it was the module behind the flywheel.  If you can start it after it cools off, that would be my first test.

Edited August 6, 2018 by lynnmor

[953 nut 51,627]

3 hours ago, Watch this Richard said:

noticed a hose on the back of the fuel pump.  Not sure where it leads 

Your fuel pump is a "Pulse Pump" and the movement of the piston generates the pulsation needed to push the fuel through check valves to the carburetor.

If the vent in your fuel cap is plugged it will develop a vacuum in the fuel tank as the fuel level decreases.

Placing a spark plug on the head while cranking the engine should show spark.