Popping when starting up.

[chef1366]

It means you tried to start it with the throttle wide open.
Use the choke only.

[tkent02]

The pilot jets i screwed in about three turns in so they would be able to suck up the fuel, could i have raised them too high? or could it be something else?

The pilot jet should be screwed in all the way.

[Tenrilid]

don't do what I did. Check your idle screw on the bottom of the carbs in between carb 2-3 and screw it all the way out and when it berely touches the plate then go 2-3 full turns in. try that then make adjustments to the screw once it starts

[tyhillert91]

don't do what I did. Check your idle screw on the bottom of the carbs in between carb 2-3 and screw it all the way out and when it berely touches the plate then go 2-3 full turns in. try that then make adjustments to the screw once it starts

what did you do out of curiosity?

[tom203]

what did you do out of curiosity?

Probably discovered that his idle stop screw was holding throttle plates too open which tends to complicate cold starts. Since you probably can't see plate position without removing stuff, best to check by backing off screw and then going back in 2 - 3 turns. As chef said, just use "choke" no throttle input.