[Ed Johnson]

Does primer squirt fuel into carb throat when key is pushed up? Or should key be pushed and held to prime while starting?

[tashasdaddy]

the primer goes straight to the intake, not the carb. when cold turn key on, push in for 6-8 count,release, then turn key. sometimes the second time you may have to hold the key in and turn. then bump key till engine settles.

[Ed Johnson]

holding for 6-8 count sounds like fuel is pushed/pumped into intake (carb output)?

thanks for reply, amigo

[Dhadley]

The primer solenoid is merely an electric valve. When the motor is cold there is no fuel pressure in the fuel delivery system (lines, pump, primer, carb throat, intake etc) so you pump the bulb to create the pressure and fill the carb bowls (we'll assume we're talkig about carb'd motors). Now that there's pressure in the line you can activate the primer solenoid. That allows fuel to be pumped into the intake system somewhere. Some pump fuel into the intake manifold and on some motors it goes right into the intake runners next to the intake ports.

When you turn the key to the "On" position and push and hold the key in (without engaging the starter) you're allowing the pressure in the line to force fuel in. Once the pressure drops no more fuel goes in until the pressure is created again regardless of how long you hold the key in. More pressure has to be created by either you squeezing the bulb or the motor turning over and activating the fuel pump. That's why it darn near impossible to flood a primer equipped motor on one line pressure.

Once you've held the key in for that 6 or 8 count you'll turn the key to "Start". The motor should fire almost instantly. You may have to "bump" the primer a time or two as the motor warms up (intake runners & reeds get wet with fuel).

The primer is only a valve, not a pump.

[Ed Johnson]

good explanation - hand "pump" on fuel line is source of pressure.