Quest Q-Jet B6-4W 2-Motor Launch Pack: FAQ for Flyers
By Quest Q-jet | Published: 2026-10-13
Category: Product Reviews
Straight answers on the Q6123 2-motor pack: what the B6-4W delivers, which rockets it fits, and when to pick it over the A3-6FJ pack.
Quick answer
The Quest Q-Jet B6-4W 2-Motor Launch Pack (Q6123) is a two-motor pack of 18mm composite motors with a 4-second delay and White Lightning propellant. Buy it if you already fly 18mm Quest Q-Jets and want a proven mid-delay motor for lightweight, stable rockets. Skip it if you need a longer delay for heavier builds or a different propellant effect; the A3-6FJ pack covers those cases.
What is the B6-4W motor pack?
The Q6123 pack contains two Quest Q-Jet B6-4W motors. The B6-4W designation tells you the key numbers: a B-class total impulse, a 4-second delay before the ejection charge, and the White Lightning propellant formulation. The pack is a simple consumable purchase, so you get exactly two flights per pack and no hardware to reuse.
Q-Jets are 18mm composite motors. They use a patent pending high-strength polymer case and bulkhead, a ceramic nozzle, and the same family of solid propellant used in NASA's Space Shuttle boosters, military missiles, sounding rockets, and NASA's future SLS moon rocket. That construction is what separates them from traditional black powder motors in the same diameter.
Which rockets does the B6-4W fit?
Any rocket designed for 18mm motors can accept a Q-Jet B6-4W, provided the rocket's weight and drag are in range for a B-class motor with a 4-second delay. The Quick-Q starter set is a natural match because it ships with a complete launch system that can fly the entire Quest fleet, so you can move from the included motor to Q-Jets without changing pads or controllers.
The practical limit is rocket weight and recovery timing. A 4-second delay is a mid-range choice: it works well for light rockets that coast briefly, but it is not the right delay for a heavy or high-drag build that needs more coast time before ejection. If your rocket is on the heavy side for a B motor, choose a longer delay rather than forcing the B6-4W.
How does the B6-4W compare to the A3-6FJ pack?
The A3-6FJ pack (Q6109) is the other 18mm Q-Jet option in the catalog. It uses Black Max propellant and a 6-second delay, so it behaves differently: the longer delay suits rockets that need more coast time, and the propellant choice changes the visual and sound character of the flight. The B6-4W's 4-second delay is the shorter of the two, which matters when your rocket is light and would otherwise drift or eject late.
Note that the A3-6FJ pack is listed as a clearance item that will be cancelled when stock is gone. If you want to standardize on one delay for your fleet, the B6-4W is the more consistently available choice right now.
What should I check before flying?
Confirm three things before you load a B6-4W: your rocket's motor mount is 18mm, your rocket's weight is appropriate for a B-class motor, and your launch site and conditions suit a 4-second delay. Also check your local rules and the motor's packaging for any field restrictions, since composite motors can carry different handling requirements than black powder.
Because the pack contains only two motors, plan your flights. Two motors means two attempts, so test your rocket's stability and recovery on a calm day before using the second motor on a windier one.
FAQ: B6-4W motor pack
- Is the B6-4W pack a good first composite motor?
- Yes, if you already fly 18mm rockets. The Q6123 pack gives you two motors with a mid-range 4-second delay, so you can evaluate composite performance without buying a larger reload system. Start with one pack, fly it in a light rocket, then decide if you want the longer-delay A3-6FJ as a second option.
- Can I use the B6-4W in any 18mm rocket?
- It fits any 18mm motor mount, but the rocket's weight and drag must be appropriate for a B-class motor with a 4-second delay. Heavy or high-drag rockets need a longer delay. Check weight and delay before you load the motor, not after.
- What is the difference between White Lightning and Black Max?
- The B6-4W uses White Lightning propellant; the A3-6FJ uses Black Max. The propellant family changes the flight's visual and sound character, and the A3-6FJ also has a longer 6-second delay. Pick the delay that matches your rocket first, then the propellant effect you prefer.
- Should I stock up on the B6-4W or the A3-6FJ?
- The A3-6FJ pack is a clearance item that will be cancelled when stock is gone, so it may not be reorderable. The B6-4W is the safer pack to standardize on. If you want a repeatable motor for your fleet, choose the B6-4W.
Product facts
- Quest Q-Jet™ B6-4W White Lightning Complete 2-Motor Launch Pack - Q6123: Quest Q-Jet B6-4W White Lightning Complete 2-Motor Launch Pack (Q6123), catalog price USD 9.12, comparison price USD 12.49. Two flights per pack at a clear discount versus the comparison price, so it is a low-cost way to try composite 18mm motors.
- Quest Q-Jet™ B6-4W White Lightning Complete 2-Motor Launch Pack - Q6123: Q-Jets use a patent pending high-strength polymer case and bulkhead, a ceramic nozzle, and the same family of solid propellant as NASA's Space Shuttle boosters, military missiles, sounding rockets, and NASA's future SLS moon rocket. The composite construction is the reason Q-Jets are marketed as advanced 18mm motors, and it explains why they behave differently from black powder motors.
- Quest Q-Jet™ A3-6FJ Black Max Complete 2-Motor Launch Pack - Q6109: Quest Q-Jet A3-6FJ Black Max Complete 2-Motor Launch Pack (Q6109), catalog price USD 7.87, comparison price USD 12.49, listed as a clearance item that will be cancelled when stock is gone. The A3-6FJ is the alternative 18mm Q-Jet pack, but its clearance status means availability is not guaranteed, which affects which pack you should standardize on.
- Quest Quick-Q™ Flying Model Rocket Launch Set - Q1409: Quest Quick-Q Flying Model Rocket Launch Set (Q1409), catalog price USD 27.59, comparison price USD 45.99, includes a complete launch system that can fly the entire Quest fleet and a rocket that needs no painting beyond self-adhesive decals. This is the entry point that pairs with Q-Jet motors, so a new flyer can buy one set and then add motor packs without replacing launch equipment.
