I have encountered this problem with about 10 diffrent Ethas about 90% of the time i have found it to be the rear poppet oring or the internal joiner oring. The poppet is a #11 and the internal joiner is a #12. When looking at the tech poster or manual it will be item number 9 and 6. They also have issue with bending the poppet springs. Those three things are what give it the weezing noise and really bad shoot down. Also I have a dislike for the stock eclipse lube (Gerry will kill me for saying this) but I prefer to use Exalts vitamin G or lurkers.monkey poo. If sending the gun in make sure you have it lubed with the provided Eclipse lube or Gerry will sometimes throw a fit about it.
They are great guns but this is there weak point also make sure to have Fresh NAME brand battery in the marker. I use Energizer MAX but Duracell will work NO Rayovac or other brand you think is name brand.....Stick with the Drumming Rabbit or Copper Top.
If you have any questiong you can call Gerry at planet Eclipse US but Gerry usualy is at an event or is smokeing so he wont answer. If you want to talk to a tech dirrectly call up Tim at Avid Extreme Sports in Dallas,Tx . He techs All of D1 Team Texas Storms markers.
Gerry Bates Planet Eclipse USA
(401) 247-9061 or firstname.lastname@example.org
Tim at Avid Extreme Sportz Dallas
If calling Tim at Avid let him know Kyle from the CIA sent you his way.