M151A2

After adjusting the mechanical valve lash for all eight valves located in the cylinder head this video shows the result of that adjustment by monitoring engine vacuum.

This is how I connected a vacuum gauge to an M151A2 engine to monitor how much vacuum was being produced by the engine before I adjusted the valve lash for the eight valves located in the cylinder head.

Preventing the metal battery box cover from contacting any three (3) of the four (4) battery posts located in the M151-A2 battery box is extremely important.

This is how I use a 24VDC, 2.0 amp pulsed battery tender to maintain my two (2) each 12 VDC connected in series batteries resulting in the vehicles designed 24 VDC pressure. I believe using a 24VDC "pulsed" low amp battery tender is necessary. Using something like a 24VDC battery charger with 10 or more amps will cause the vehicles ignition coil to stay sourced and possibly overheat and fail resulting in charged batteries but a engine cranks but will not start condition.

This video will demonstrate the fuel flow into a M151-A2 fully warmed up (160F) engine as well as demonstrate that pumping the gas pedal on a M151-A2 Army jeep does not add fuel into a carburetor only the engine's pistons up and down movement creating vacuumpulls the fuel from the carburetorfloat bowl into the engine. At the end of the video when I turn off the ignition thus turning off the engines ignition (spark) you will see how the engineer designed the Zenith carburetorto allow the final few engine piston vacuumpulses with no spark at the spark plugs to pull fuel into the carburetorto better aid the next engine startup.

Pumping the accelerator pedal, gas pedal, does not add fuel into a Zenith carburetor on a M151 Army jeep. The fuel is only drawn into the carburetorbecause of the vacuumcreated by the up and down motion of the engine pistons be it during engine cranking (starting) or during running. There is no accelerator circuit on this Zenith carburetor so pumping the gas pedal is useless. But there is a Full speed and Main metering fuel circuit that will allow fuel to be added but only if the vacuumcreated by the up and down motion of the engines pistons pulls the fuel from the carburetor float bowl into the carburetor itself.

This is how to best start a M151 when cold, below 40F degrees. You only have so much battery pressure, 24 volts, to get the job done and its cold out so your vehicle batteries don't really want to work anyway.