CUSTOM VALVE & PISTON for Crosman 1377 1322 1300KT Drifter 2289G PC77

Description: This listing complies with eBay's air gun guidelines found here and I will only sell and ship air guns to buyers in jurisdictions where permitted by applicable laws - http://pages.ebay.com/help/policies/firearms-weapons-knives.html The valve is not a modified Crosman valve, it's re-designed for maximum power and consistency and machined from 7075-T6 aluminum bar stock. We are the only company in the world producing a completely-custom re-engineered valve for these models. This is the Magnum Airpower CUP-SEAL VALVE & PISTON KIT. The valve-halves can be rotated to either side to align perfectly with the port and mounting-screw holes in the pump-tube which are often not square with each other from the factory. The factory valve and custom valves sold by others aren't designed to allow this because all of them are factory valves, modifications or not. The valve body has a larger ID, the cap is larger ID with shorter threads and a deeper chamber, the valve-stem seat is further forward which allows the pin on the valve-stem to stick out a little further so it has a longer throw. The combination of all these enhancements means it can hold more air than any other 13XX custom valve on the market. Due to the pin on the stem sticking out a little further and the short angled port it empties faster and more completely with less hammer force. It's the same outer dimensions as a factory valve. The piston head and locking collar is machined from 7075-T6 aluminum, one of the strongest of all commercial aluminum alloys, stronger than many types of mild steel and stainless steels only much lighter. The custom piston pin is machined from tool steel with radiused ends to match the internal tube contour, this reduces scoring and makes pumping smoother. The piston-base is machined from Delrin for ultra-smooth function and to act as a compression-buffer to help protect metal parts from excessive stress. The piston rides on the Delrin base and cup-seal with no metal-to-metal contact to reduce scoring, wear and work smoothly. The cup-seal produces a shot to shot consistency generally within 4-5 FPS which greatly enhances accuracy, almost as good as our flat-faced kit, but with much less maintenance, especially in dusty or dirty environments. These parts work well at 4-17 pumps. Other sellers advertise kits that allow you to put 30-40 pumps into their valves, this is due to their valves needing 30-40 pumps to equal the power of our custom valves at 15-17 pumps. Our valve holds more air than most others, our piston produces more pressure than most others, our port and valve-stem seat specs empty the valve more completely with less hammer-spring force, so you get the same or more power then their parts produce with less pumping. Once the piston is adjusted to length, snug the locking collar down with a pair of soft-jawed pliers while holding the base with a 3/16" pin punch or similar tool. Thick strips of folded paper, cardboard or leather can be wrapped around the locking collar to keep it from being marked by standard steel pliers. It's not necessary to torque the collar extremely tight, just snug it down moderately for the best overall function. If the piston is adjusted too long it won't allow air to enter the tube when the pump lever is in the open position, if the gun won't pump up then this may be the cause. The valve stem sticks further out then the original factory valve, it's often necessary for the hammer to be in the cocked position for the valve to hold pressure. The valve exhaust port is radically angled to produce more power. Because it's angled the opening looks oval rather than round. This is not by mistake, it's supposed to be this way. The transfer port gasket fits and seals effectively with the .150" ID of the port, do not enlarge the port ID, it will not seal with the gasket correctly if you do. Further enlargement of the valve port will not gain more power, matching your transfer port and barrel port to the same .150" diameter will at higher numbers of pumps. We also have a flat-face kit listed which produces a shot to shot consistency of around 2 FPS and more power at up to 10 pumps, that version falls behind the cup-seal version above 12 pumps but works better for those who want to pump as little as possible to get better than factory power and consistency. INSTALLATION : You will need a wooden dowel to install the valve without damaging it or the tube. 1/2" Diameter by 12" or longer works well, hardwood is better but softwood will work also. The valve seals internally with an o-ring. The two halves should not be twisted tight together, there should be a slight gap between them. This allows the position of the port to be adjusted to either side to align with the hole in the tube. 13XX tubes have those holes slightly out of alignment, some much more than others. Being able to adjust the port position by twisting it to one side or the other is necessary for correct alignment. Once the valve is in position, put the trigger frame in place and install the front frame screw lightly, this holds the valve cap in place while you adjust the port. Use a pin-punch, hobby paintbrush handle or similar object to gently turn the port until it's centered. Placing the gasket on top of the valve helps to check if it's centered. Once centered, push the valve in tight with the wooden dowel to make sure it's seated snugly against the stop in the tube, then remove the dowel and tighten the frame screw firmly. The piston needs to be adjusted correctly to work well and avoid damaging the gun. On the first pump (no pressure in the tube or valve) the forearm should close with moderate resistance, not need to be forced. Once it's adjusted to close without forcing it, fire the air out of the valve and without opening the forearm all the way check how much clamping force it has with no pressure in the tube. The piston should compress against the valve face with light to moderate clamping force to hold the forearm up snugly. After making an adjustment, fire the air out of the valve before checking it again. With the flat-face piston you can leave the o-rings off to adjust the length, this allows you to feel how much tension there is without pressure in the tube. With the cup-seal piston, during the installation process, you can use the wooden dowel to tap the valve-stem open and fire the gun, the air will escape through the barrel so you can feel the fit and function of the piston without pressure. Always make sure the valve port, or barrel if the gun is assembled, is pointed in a safe direction before firing the valve, the air pressure is strong enough to cause injury even when the gun is unloaded. Oil the outside of the valve, piston and seals before installing. We made these valves fit tighter than the original factory valves for performance reasons. They seal better at the o-ring and transfer-port gasket because there's less gap between the tube and valve. This reduces pressure loss during pumping and firing producing more power. The valve should be pushed into place with the wooden dowel. If your tube is bent, dented from hard pumping or has deep stamped lettering the valve may fit too tight. We tested dozens of new and used tubes to make sure the valves fit correctly in most cases. If the valve fits too tight to go in without forcing it, use a different tube or fix the issue as explained in the next paragraph. HOW TO FIT A TIGHT TUBE: 13XX Valves sometimes fit a little too tight in the tube, this is caused by the tube being slightly bent, not perfectly round, or from the stamped lettering dimples on the inside of the tube being too deep. Some tubes have deeper stamping than others so some are a tighter fit. Use a 2" wide strip of wet/dry sandpaper in the 300-400 grit range wrapped around the 1/2" wooden dowel, attach the strip to the dowel with a piece of duct tape and wrap it tight. Trim the length of the sandpaper until it fits snug into the tube without forcing it. You're basically creating a sanding drum on the end of the dowel. Twist the dowel to get the sandpaper into the tube without it unraveling, twist the drum down into the tight-spots and continue to twist for a couple-dozen rotations. Repeat this process until the valve fits without forcing it. Once the fit gets close to perfect, use oil on the sandpaper to get a smoother finish but don't polish the inside of the tube too much, over-polishing will cause the piston seals to bind which makes it harder to pump and can damage the piston seal. We use this method in our shop except the sandpaper is attached to a piece of rubber hose on a steel rod and we use a cordless drill to spin it which takes about 10 seconds to complete the job. If you have a drill with a 1/2" chuck you can use that to turn your honing-dowel. Doing this by hand only takes a few minutes in most cases, you don't generally need to remove much material for the valve to fit. If the tube still fits tight and this process doesn't seem to be working within a reasonable amount of time, your tube may be too far out of spec and you might be better off replacing it. Some tubes are bent or not perfectly round from something going wrong during the stamping process when they are manufactured, even factory valves fit extremely tight when the tube is too far out of spec. LUBRICATION : Variable-pump models should be assembled with oil to lube all the seals and moving parts. Add a drop of oil directly into the pump chamber every couple hundred shots. You can do this more often if the piston isn't working smooth or produces inconsistent performance. If you accidentally over-oil you can fire the gun with the barrel pointed straight up, unloaded and safely away from you. In that position excess oil settles near the valve stem and blows out through the barrel. To prevent oil-lock, only use two pumps for each shot until excess oil is cleared from the pump chamber and valve. A drop of oil should be applied to all pivot points of the pump lever and one at the back of the piston seal. This will lubricate the contact points of the piston.

Price: 122 USD

Location: West Hatfield, Massachusetts

End Time: 2024-07-07T00:50:51.000Z

Shipping Cost: N/A USD