Briggs 18hp Twin only runs on starting fluid (1 Viewer)

[sean2202]

Long story short my work acquired a 18hp Twin Vanguard Briggs in a mower that had been sitting since 2-2012. The engine cranks strong but will only fire if sprayed with starter fluid or gas from a squirt can.

This is what has been completed.

• Fuel tank drained and flushed with clean fuel
• All fuel lines and fuel pump pulse line replaced with new
• New fuel filter
• New plugs
• Checked compression. 160 rear cyl...170 front cyl
• Replaced fuel pump with a known working unit
• Checked fuel shut off solenoid...good
• Installed differerent carb but unsure if carb was good.
• Original carb ran on start fluid and replacement carb was the same
• New carb on the way but unsure if that is exact problem
• Checked operation of govenor..seems ok
• Fuel shutoff valve works and fuel does travel to carb
• New battery
• Cleaned all mice nests from around piston cooling fins.
• Checked all wires for mice damage.
  
• Oil and filter changed as well.

What have I missed? Any help is appreciated.

 

[4x4veteran]

Gasket between carb and port sealed? Possible vacuum leak there?

The spray could be working like fuel injection forcing fluid past the leak.

Have you tried squirting a bit of gas in and seeing if it will run?

 

[sean2202]

Good thinking on the gasket. Gasket was ripped slightly upon removal and I used a dab of form a gasket to see if it would run on the spare carb. The gasket was probably shot from sitting as well. I have ordered all new mounting gaskets along with the new carb.

I used gas in a squirt can feeding the carb and engine would run as long as I kept
Feeding it.

Here is a pic of what gas can do sitting in a carb for 6 years. (Float and top gasket not shown)

 

[D'Animal]

Have you checked the fuel pump?

 

[sean2202]

Installed the new carb with all gaskets making sure all old gasket material was removed. Engine fired right up and ran great.

One other item I did check after my original post was the gas cap as it has a vent in it that I thought may be plugged restricting gas. I removed cap but engine still did not run.

 

[4x4veteran]

Installed the new carb with all gaskets making sure all old gasket material was removed. Engine fired right up and ran great.

One other item I did check after my original post was the gas cap as it has a vent in it that I thought may be plugged restricting gas. I removed cap but engine still did not run.

View attachment 1629535

Glad you got it running. One other thing you might check out is the muffler. Take it off and bang it hard enough to loosen any stuff that might block the flow.
I have a 16 hours V that is 20 years old.
I still use it in the summer.
A year or so ago it started losing power.
After adjusting the valves and cleaning the carb and other tinkering to no avail it dawned on me there might be to much back pressure on the exhaust so I did what I suggested to you and a bunch of crud came out now the mower zips up the hill fine.