The o-rings included with the wide-bore gauge port are now a slightly smaller size that installs into the tube a lot easier. Two extra sets of o-rings are automatically included.
These upgrade parts fit Discovery, Maximus, Marauder Pistol, 1701P, 1720T and custom PCP builds. The gauge can be mounted directly into the wide-bore port if a low profile is desired. The extension allows the gauge to sit at the correct height for the stocks on Discovery and Maximus models.
The 3500 PSI GAUGES shown in the main photo are standard Crosman/Benjamin parts. I have discontinued those due to leaks and other quality control issues. The 1200, 3000 and 4000 PSI GAUGES are much better quality. The 1200 is great for CO2 which generally ranges from 600-1100 PSI in cool to hot temperatures. The 3000 I generally use in Maximus and Discovery models operating up to about 2800 PSI. The 4000 works best for 3000+ PSI.
THE THREADS ON THE 4000 PSI GAUGE ARE THE CORRECT 1/8 NPT SIZE BUT FIT TIGHTER THAN THE ORIGINAL GAUGES. IN MOST CASES THIS IS GOOD, THEY THREAD IN SMOOTH BUT TIGHT 2-3 FULL TURNS. 2.5 - 3 TURNS IS REQUIRED. MORE IS OK IF IT THREADS IN SMOOTHLY. ON RARE OCCASIONS ONE WILL FIT VERY TIGHT AND REQUIRE MORE FORCE. THREAD TAPE OR SEALANT ACTS AS A LUBRICANT TO PREVENT THREAD DAMAGE AS THE THREADS LOCK TOGETHER. THIS IS HOW THESE TAPERED THREADS ARE DESIGNED TO WORK. ON RARE OCCASIONS THE THREADS FIT EXTREMELY TIGHT. DO NOT FORCE THE PARTS TOGETHER IN THIS CASE. THE SOCKET YOU'RE THREADING INTO MAY SIMPLY BE TOO SMALL FOR THIS GAUGE. STANDARD MANUFACTURING VARIANCES CAN CAUSE PARTS MADE BY DIFFERENT MANUFACTURERS TO OCCASIONALLY NOT FIT TOGETHER WELL EVEN THOUGH THEY ARE SUPPOSED TO BE MATCHING SIZES. THIS IS A COMMON ISSUE WITH GAUGES ESPECIALLY, SOME FIT TOO TIGHT, SOME TOO LOOSE. THE 3000 PSI GAUGES I HAVE LISTED HAVE SLIGHTLY LOOSER THREADS AND GENERALLY FIT BETTER WHEN THE 4000 PSI GAUGE IS TOO TIGHT.
The WIDE-BORE GAUGE PORT has a much larger air passage than the Discovery and Maximus ports do. It produces more power when used in those models. It also takes up less space in the tube allowing more room for air. The difference in inside diameter compared to the Discovery and Maximus gauge ports is compared in the last photo. It is made of brass with a black oxide coating for extra corrosion resistance. It includes upgrade 90D o-rings. The o-rings for this port are thicker than the ones on the Discovery port. They are the same size as the o-rings on the Maximus valve. This port does not seal against the extension or gauge with an o-ring, thread sealing tape or high-pressure sealant should be used. Extra o-rings are available in the UPGRADE O-RINGS listing, only the newer o-rings that install easier are available now..
The HEAVY-DUTY GAUGE EXTENSION is made of high-strength stainless steel and is rated for operating pressures up to 6500 PSI. It is far stronger than it would ever need to be and extremely corrosion resistant.