Level 10 powertube oring

[bsmith61]

Hi, I'm new here; and to Auto/Minimags and paintball. I've read through a lot of the explanations about redoing the orings on the valves and whatnot. I have a Minimag with Level 10 upgrade. Other than that, it seems to be a pretty stock unit; I got lucky and walked right into it when I asked a buddy about paintball. He said he used to play alot but hadn't played in years. He sold me his gun and tanks in a lot for a very good price. Now that I've played with it a little I like it a lot, but it won't do me any good if I can't keep it working right. There was some venting issues, and upon inspection I found that some of the orings were dry rotted.

So, after reading a lot of stuff on this forum and ordering the parts to replace all the orings i encountered an issue with the powertube carrier and powertube oring that goes inside the carrier. I understand what this does, and have read the installation guide. The new powertube orings I received from AGD fit inside the carrier, but are very loose on the bolt stem (they all vent gas out of the powertube when it's reassembled). The powertube oring that came with the gun when I got it is still in one piece and fits more snugly and fortunately doesn't vent gas.

Being as I got it used, I don't have any spare parts so I can't experiment to see how it all works (different sized carriers).
So I understand what I'm supposed to be trying to do, my actual question is this: are the different sized carriers intended to compress the powertube orings;' inside diameter to just the right size to fit the bolt stem because all of the powertube orings come from the manufacturer slightly different sized?

Although the powertube oring that came with the gun is working for now, I know it won't last forever, so I'll need to know what I'm trying to accomplish as I order the different sized carriers to work with the new powertube orings.

Sorry for the droning on, but I didn't want to just put it up piece by piece, making everyone read twenty posts to figure out what I actually need.
Thanks in advance for any help...

[vintage]

yes, each carrier is designed to make the one o ring a tighter fit on the stem. they more lines and dots on the outside the small the internal diameter of the carrier and the more it compresses the o ring. the rule of thumb is start with the most open and work down from there, its the plain carrier, the single dot is next.

[athomas]

The carriers are sized using lines and dots. Each line represents a 1 and a series of dots represents 0.5. Eg; 2 lines and dots equals size 2.5. Carriers range from size 0 to 3.5 but most people only have from 0 to 2.5 and most new kits have even less.

When tuning your level 10, remove all the shims from the powertube before starting. They don't affect the operation but they can cause false leaks which cause you to use a carrier size that is too tight. Don't put them back when you are done. You shouldn't ever need them.

For carrier sizing:

Find the carrier size that causes the installed oring to fit freely over the bolt stem. The carrier should sit on the bolt stem without moving if the bolt is held in a vertical position. If you tap the valve on a hard surface, the carrier should be loose enough to allow the bolt to move. If you have to force the carrier onto the bolt stem with any force at all, then it is too tight. Install the bolt and valve into the gun. When aired up there should be no leaking. If it leaks, take the carrier out and replace it with the next smaller size. Always use the same white carrier oring in each carrier that you use. It is the oring that you are adjusting. Try it again. You want to use the largest carrier size that does not produce a leak.

Any time that the gun fires and does not reset or short strokes and does not reset, or just chuffs and does not reset, the problem is most likely a carrier that is too tight. Installing shims will not help. Shims only help if the bolt moves, hits an object but does not vent any air, and then cannot reset because the chamber is still fully charged. Most of the time the bolt always moves far enough to expose the vent hole, get rid of excess air, and then reset.

For spring adjustment:

You want to use the bolt spring that allows you to shoot about 20fps above the lowest velocity that the gun will cycle at. So, if you want to use the gun at 280fps, then your desired lower limit of operation is 260fps. Insert your long bolt spring. Turn the velocity adjuster down before you air up the valve. Then gradually turn up the velocity until the gun will cycle. This is your lower velocity. Measure it. If it is above 265fps, then you will need a shorter spring or you will need to clip the one you have (unless you have red one. They are usually in the correct range). If you clip a spring, only clip half a coil at a time and then try it using the same procedure of starting with a low velocity setting. Make sure you put the cut end of the spring towards the bolt. If you have the short spring installed, and the lower range is 30fps below the desired shooting velocity, I wouldn't worry about using a stiffer spring and would just go with the short bolt spring. If it was much lower than that, I would definitely clip a long spring to get closer to the desired range.

[bsmith61]

Thanks to you both for your answers. I feel like I have a better understanding of what's going on with the powertube and bolt. I will have to order a carrier one size smaller than I have now because all of the the powertube orings that I just received easily fall down the bolt stem when in the current carrier without having to be pushed down; maybe the next two sizes, actually. Of course, as soon as I order them, the guy I bought the gun from will hand me a box of parts and say, "hey, look what I found in the attic!" Such is life I guess.

This has been a big learning experience, learning how the valve operates one section at a time. The old videos posed here were a big help too! I got it completely refreshed this afternoon (all but that old powertube oring in the carrier), and it really shoots well. I'll be 'relaunching' it into the world of paintball combat this weekend. Wish me luck!!!

[Cyco-Dude]

yes, each carrier is designed to make the one o ring a tighter fit on the stem. they more lines and dots on the outside the small the internal diameter of the carrier and the more it compresses the o ring. the rule of thumb is start with the most open and work down from there, its the plain carrier, the single dot is next.

that's backwards; the more lines etc it has, the larger the carrier, and vice versa.

[vintage]

that's backwards; the more lines etc it has, the larger the carrier, and vice versa.

still learning my first level 10