xvalve problem??

[fire1811]

ok i can usually figure my own stuff out but this one has me stumped.

went to play with my ule mag with xvavle last weekend and i aired up the gun and it wouldnt shoot. pressure on the trigger rod but wouldnt fire. so i took it all apart and oiled the crap out of everything. also after the gun sat for a few minutes it would chuff so i droped down a carrier, since i asummed it was leaking around it.

now my problem is i cant get my velocity under 300fps?

if i turn the velocity screw in for more pressure the gun will allow me to fire but its shooting at about 320s to 340's. i can back the velocity nut out to get down just below 300 but it still spikes over. and the kicker is when i bleed the air and reair it up i have to jack the velocity back up to shoot, and then back it down again.

velocity seems pretty erratic also, paint bore is good but will vary sometimes 20fps.
havent played with the sear length so i dont think its that?

set up is
xvalve
lvlX with .5 carrier and 3 shims, med spring
ult

pureenergy tank.

any ideas?????
curt

[athomas]

If the gun is chuffing after it sits for a while, then your carrier is too tight. Go to a larger size. This will help with spiking and help lower the velocity as well as make the operation more consistent.

Also, put a lighter bolt spring in. This will allow you to shoot the gun consistently at a velocity under 300 fps.

[fire1811]

k just tried the 1 carrier and it leaks so i droped back to .5 and then the shortest spring and no shims. wouldnt reset so i added 3. and it leaked down barrel. put one in and its shoots fine.

i aired it up and it leaks down barrel. had to turn velocity up to get it to shoot. its now shooting at the same 320's as before???????

anything else?????????

[Eatem Alive]

how about the tightness of the thumb/ field strip screw. i've had that problem before. the gun would have pressure on the trigger but wouldn't fire. i had to fiddle with the screw tightness until it was just right. stupid thing!

[fire1811]

tried that also. tried different tightnesses for the fieldstrip screw and the grip frame screw?

[alooney11]

your velocity problem is wierd what type of spring are you using? With the tightening of the grip frame screws.... hand tighten the grip frame screw(one closest to barrel) and then go about a half turn with an allen key, or until your bodydoes not wiggle. Then start shooting(withthe marker fully assembled) until you get the bolt stick....when it sticks do nothing keep it stuck, and then start to tighten your field strip screw(one under the x-valve) until you hear the bolt click into place. This works spread the word, its an issue with the flexibility of the new aluminum bodies. reply tell me how this worked.

[fire1811]

k will do that with the screws.

but i was originally using the middle spring with no problems. put gun away for two weeks and took it out to play last sunday and started having all these probs.

switched to small spring and still have same problem

[CaliMagFan]

use the stock spring to get teh marker up and running.. then go to the med when you've resolved the problem.... i could be the FS screw, but you will usually get teh marker to fire at least once or twice in a strain, then a stick if that is the problem....

one of other thing is the reg piston might need oil... if you feel comfortable opening the valve halves and pulling th reg piston out to oil it, do so... good luck and keep us posted...

-kyro

[fire1811]

i can get it shooting if the velocity is way up but cant get it down enough to be legal.

i already oiled up the reg piston also.

one thing i noticed and im not sure about is the velocity nut is only about 1 or 3/4 of a turn from being all the way in? if i back it out anymore there is not enough pressure to shoot the gun

[athomas]

Use no shims until you get it working without leaks. Shims allow you to fine tune it but you should get it working without any shims first.

How long have you had the gun? How many times has it been fired? Check the sear for wear at the tip. This could cause the bolt to sit forward causing your leak.

[fire1811]

i built the gun in july and its worked perfect since then. about 2-3 weeks after i got it i had to drop down a half a carrier since lvl x got broke in. and its been fine since.

is it possible the the pureenergy tank is inputting to much pressure? i ordered a guage to test it?

[CaliMagFan]

entertain these ideas for a minute....

try a diff tank...

nothing in the reg is in backwards?.. i know its stupid, but you never know..

sounds like your velocity nut is much farther in than any other i have seen in a working mag... try backing that out... maybe you just have it so high its causing instability... you'd think it would vent, but i've heard stranger things happen to more common folks..

-kyro

[fire1811]

i will try the velocity nut today when i get home. dont think it will work though since i have had to keep turning it in to get the valve to shoot.
man this sucks

[fire1811]

ok think i figured it out.

got a guage and my tank was outputing 1200psi????????????
supposed to be 850 but hey its a pmi.

anyway though trial and error i rearanged the bevel springs to make my output about 950psi

tightened the gripframe and f/s screw and gave it a shot.

well it SEEMS the my baby is back to normal. chronod 284 281 284 280 286 so i cant complain about that any.

also let it sit for 15-20 min and it also seems that my first shot problem is gone.

tweeked my ult trigger kit light enough that is CAN be walked, with no trigger bounce. thats something i have been trying for a LONG time.

thanks to all those that helped i will let you know if anything changes.


question though wouldnt a higher input from the tank mean that i needed to turn the velocity nut in LESS???????