QB78 questions

[jonnnyboy]

Oh what a beautiful day!!  Barely into the 60's and the fish were biting this morning!  Sorry, I just needed to tell somebody!!!!  :p

Since it was so pretty today, thought I would take the qb78 out and fire off some of the Industry Brand pellets I just got from Mike Melick.  When I filled up with co2, to my surprise there was a hissing from the breech and when closed, the hissing came from the barrel as well.  I got about 8 shots off before running out of gas.  I have three questions:

First, is this a seal problem or a valve problem?

Second, is it hard to fix by someone who is maybe a 6 or 7 on the mechanic ability scale?  Yes, I know I can send it back to Mike, his warranty is superb.  But to be honest, I hate to bother him.  Would it be feasible to try a fix myself or should I give up before messing up?!?!

Third, did I cause this myself?  What I mean is, I leave the gun charged, cocked and with the bolt closed.  Would that cause an eventual leak?


I don't speak much on the forums but love to hang around the edges and listen in and just want to say thank you to so many who have taught me unawares about this wonderful hobby.  My son and I have really enjoyed a newfound shared hobby.

Joe

[yel01z06]

if i were u i would shoot mike an e-mail and c what he says and go from there i do not know if by u taking it apart will void your warr.

[Bentong]

Try pellgun oil or non-detergent 30 wt motor oil or auto transmission fluid before doing anything else..most times this fix it. It rejuvenates the seals. Use the oil on the tip of the co2 that you put in first and just use a used one for the back so in case it still leaks you just waste 1 cart if that don't work need to replace valve o-ring or clean the valve for contamination that's fouling your seals ( o-ring or stem seals).

[DANULSON988]

charge one c02/Use one empty, cock bolt and close it. then place the tip of the barrel into water, if it bubbles out the barrel end, The valve stem is leaking. This can be caused by dirst and or lint stuck on the stem of the valve.

[mikeiniowa]

If you leave the rifle with the bolt closed and cocked the hammer spring will weaken over time, when done shooting pull the trigger then close the bolt so the spring is not under tension....

[D R Greysun]

John,

If it didn't leak in storage it shouldn't leak after a refill.  The 'valve seal' is leaking, most likely because of debris on the seal surface.  The valve will need to come out and the debris removed.  Or, you could try it one more time using one cartridge.  Some times the debris will be blown off the valve seal.

D R

[jonnnyboy]

Well, I've been researching the forums and found some options.  The best and most recommended one is putting the pellgunoil down the tube, letting her sit awhile and then seeing if the co2 blows the trash out.  I've put the oil in it (just a couple of drops) and she's sitting pretty in the corner just soaking.  Maybe there will be a few moments this afternoon to drop a cart in and see if it works.

Also, got an encouraging email from Mike with some advice that I hope to try if that don't work.  Just wanted to say again, thank you for all your responses to help a newbie.  I am having too much fun!

[daiboy1234]

hiya guys Dai here form over the pond int he good old UK any one got any nice pics of there qb79.79 who willing to show me and tell me what you think of thsi lovely gun, so dont be shy coem say hi to dai.show me all you got guys

YOURS
Dai