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  4. Holley 847, 897 Technical
  5. Holley 847 Troubleshooting
Is Your 847 Flooding on Start Up?

The Holley 847 choke plate has a poppet valve. The purpose of this valve is to open on start up so that the air isn't choked completely causing a too much fuel condition. Make sure the poppet valve is not sticking. Remember that only vacuum is used to open this valve.

What if the Poppet Valve is Missing From the Choke Valve?

Just the opposite from above. With the valve missing, there may be too much air entering the carburetor in a cold engine condition thus starving the engine of necessary fuel. If you have a "hard to keep running when cold condition" check out the choke valve and poppet valve. When cold the poppet valve will be closed.


Gas is running out of the top, or you get a strong gas smell? This is a sign of flooding. What is flooding? Simply, there is too much gas getting into the float bowl.

Here is a list of items to check when this happens:
  • Fuel pump pressure - check with your motors manual for the correct pressure. New pumps are especially suspect.
  • Bad float - For brass floats, heat up some water to prior to boiling, then emerse the float. There should be no bubbles.
  • Check float level
  • Make sure float isn't binding - move it up and down by hand and see if you feel anything catching.
  • Make sure float doesn't rubbing somewhere.
  • Does the seat have a gasket?
  • Did all of the old gasket get removed?
  • Look for any cracks around the area the seat screws in.
  • Maybe the viton tip on the needle is damaged. There should be no pressure put on the needle when adjusting the float.

Accelerator Pump

No spring is used below the accelerator pump.

Main Discharge Check Weight is Missing
No check weight available, but you can use most anything in it's place. A 2nd check ball, or a piece of welding rod. Just be sure that there is room for the check ball & weight to move up when it need to. 1/8" or so would be fine.

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