Help With Pro-Lite

I just got a used pro-lite and it is malfunctioning . With the tank hooked up , it will sometimes fire correctly , then "tri-burst" then go full auto and can't be stopped untill you unscrew the tank . I know the tank isn't low on air because I tried it on another gun . I also tried a different used bolt and it does the same thing . Another thing I did was replaced the sear spring, thinking it might be weak .

I am not expert at these , I just have 3 of them and one for parts .

What do you think is wrong ?

If I need a part, can I still get parts ? These guns are so indestructable , I hate to have one not working correctly.

Thanks so Much,

Raz

 

Okay, here are the big things to look for on a pro-lite when it malfunctions like you described.

1. Is the hammer o-ring worn, torn, or missing
2. Is the sear's catching edge worn down?
3. Is the catching edge of the hammer worn down?
4. Is your velocity screw backed out very far, or missing completely?
5. Are you missing the valve-stop? (Little square piece of metal inserted under the valve through the bottom of the marker and held in place by the front grip-screw thread-tube)
6. Is the power-tube worn down on the little bar that crosses the power tube at the valve?
7. Is the drive spring old? Cut shorter? Or is it very stiff?
8. Is the ball-detent in and facing the correct way?
9. Has the linkage rod retention screw (the rear sight set screw) been set in the hole provided for it?
10. Is the rear-sight at the middle of the marker where the set screw indentation is located (it isn't and adjustable sight contrary to popular belief)

If it is the o-ring, replace it
If your sear is worn, replace it
If the hammer is worn, replace it
If the Velocity screw is backed out too far, it will allow too-much air to escape the front of the marker and the valve doesn't have enough pressure to push the hammer back, this is common in the older-valve series. Try dry-firing the marker and see if it causes it to "auto-fire". If it is the velocity screw, get a stiffer drive spring to increase the amount of air that travels through the valve which will raise the velocity, then, use the velocity screw to turn the velocity back down by screwing it into the marker.
If the valve stop is missing, the valve can travel too-far forward or rear-ward and this too can cause back-pressure issues and cause the hammer to not re-seat properly
If the power-tube is worn at the back end, it means the valve has to travel forward more to release the propellant which can cause the non-cocking issue
If the drive spring is old or cut short, you may not be giving the valve enough force to open fully and force the hammer back. If it is way too stiff, it can keep the hammer from being able to come all the way back before attempting to force it forward again. The too-stiff scenario is rare at best though.
If the linkage rod retention screw (sight screw isn't in the proper place or is tightened down too-tight (where it actually cuts deeper than the indentation does) it can cause drag on the linkage assembly and cause the issue, this too is very rare though. The same issue applies to the screw not being in the right place.

Also, make sure the guide rod is in place in the end cap with the spring around it, the spring binding up without the guide rod to hold it in position can cause this issue as well.

Also, if the ball detent is in backward, it will cause drag on the bolt's travel and can cause the same issue.

I know it's a lot of info, but I think I covered all the bases.

Yes, in this case dry firing is with the CO2 hooked up.

There is no "ball park" for adjusting the VAS. The only safe way to do it is with a chronograph.

Yes, the Hammer, and the Rear Bolt are the same thing.

its more like you are calling the rear bolt what actually is the hammer, but it is worn to much if they sear has scratched its shape into the hammer or the sear is no longer square on the end that hold the hammer, it should be fairly obvious

if it was a former rental im going with worn sear

Edited by AngelSlayer - 07 January 2007 at 5:54pm

I just took the spring out of one of the good pro-lites and tried it in the "bad" one and it still did the same thing .

I did notice one thing , and please excuse my technology on this one.

The thinwall aluminum tube that runs inside the front bolt that sticks out when you have the gun cocked . It is worn on the top at an angle from the bolt . It is probably worn in from the edge an 1/8 -3/16 of an inch .

This won't create this problem will it ?

I am a journeyman tool and diemaker by trade and know how to tig weld very well . What would happen if I built up the end of the sear that contacts the rear bolt ? Or do you think it will be the end that actually contact the trigger ?

 

Thanks guys so much for you help.

Raz

 

It might be the power tube, is it worn so that it might cause drag on the bolt on the backward stroke? The more likely culprit is the sear though, especially since it is an old rental pro-lite.

$10 gets you a new one from tippmannparts.com

Pro/Lites can be strange sometimes, shoot few balls out of it and see if it still happens. I have had them do this dry but they shoot fine with paint.

that might have done it, it'll tri-burst without rounds in it because it
depends on the pressure build-up behind the ball to help with the blow-
back pressure to push the back-bolt into place. My prolite, indeed, most
prolites, have that issue.