How To: M4/M16/CA33 Hop-Up guide
This guide is being written to help players who want to either change their hop up unit, are assembling a new hop-up unit, or have decided to put in a new barrel or hop-up bucking.
This guide starts off assuming that you have already removed your barel and hop-up chamber from your gun.
Users only wanting to change the bucking, or replace their barrel, will want to follow steps 1, 2, 7, 8, 12, 13, 14 in that order.
1. Begin by removing the hopup and barrel from the gun. Turn the hop-up off.
2. Remove the barrel from the hopup assembly. First remove the retaining clip, Make sure the hop-up is off, then pull the barrel and bucking out of the hop-up assembley. The hop-up bit may also fall out at this time. If you just want to change the bucking, skip ahead to step 7.
3. Next, remove the large gear on the outside of the hop up. This is the one furthest to the back of the unit.
4. Now, pop the retaining clip off of the middle gear, and remove the gear.
5. The last gear to be removed has a retaining clip on the back side. Remove the clip, and take the gear out.
6. You can now remove the retaining pin that keeps the hop up arm inside the assembly, and pull out the arm, the hop up bit may be stuck to the arm, and it should come out with it, or just drop out.
7. With the disassembly now complete, you can now install your new bucking. Begin by sliding the bucking over the barrel, make sure the ridge on the inside of the bucking aligns with the groove in the bottom of the barrel. Slide the barrel and bucking into the hop up unit. Now install the retaining clip.
8. Align the hop-up arm in the unit, and put the pin in. Place the bit in the "u" shaped channel of the hop up arm. Now push the arm all the way into the unit, making sure the spring goes into it's guide at the front of the unit, and that the bit doesn't fall out of it's channel. This process is much easier if you flip the barrel/hop up assembly over. if you are folloeing the steps to change barrels or the bucking, skip ahead to step 12.
9. Now just reverse the dissasemly procedure to reassemble the hop up. Start with the gear at the front of the unit. Place it into the unit, and put the clip on the back side.
10. Now put the middle gear in, and put it's clip in place.
11. Finally put the large gear on, and screw it into place.
12. Turn the hop up all the way down and look down the barrel, there should be no obstruction from the hop up.
13. Now turn the hop up all the way on, and look into the barrel, there should be a large bulge sticking into the barrel from the hop up.
14. And there you have it. All thats left now is to put the gun back together and make sure everything works.