trracer/maverick velocity can be a mess... so i'm gonna start with the detents.
my maverick has a spring detent, and unless the previous owner removed the detent for some reason i think the trracer would have one too. to see the spring detent just remove the gripframe...
(two thumbscrews, on in front, and one behind the grip. be careful when you remove it because it's the only thing holding the internals in the back of the gun, if you have the gun pointed in the air everything will fall out the back when you remove the gripframe)
and you should see the detent spring on the underside of the gun, just in front of the hole that the front thumbscrew threads into.
it's possible the trracer actually doesn't have a detent, but i think it would since the maverick has one.
now here's the thing about the detent spring, mine was just about useless. i fixed that by folding up a small piece of paper and sticking under the detent spring so that the gripframe holds it in place. (i used an index card folded so that there are four layers, if you know what i mean) if you are using smaller paint, you may need more paper to prevent double feeding.
now for the velocity.
the velocity adjusting tool is basically a long allan wrench. and you adjust velocity down the barrel. i believe only some trracers came with the adjustable bolt. my suspicion is that the venturi bolt cannot be adjusted. did the gun come with the original bolt? if you hold the oringional bolt in your hand you should be able to look through it (front to back) and see a hexagon shape. that hexagon shape is what you must turn using the velocity adjustment tool. turn right to raise, left to lower (this is if you're looking down the barrel).
if the venturi bolt cannot be adjusted, which i suspect is the problem, you will have to use springs. a harder or longer mainspring will raise velocity, and shorter or softer mainspring will lower it. i suspect that extra spring you describe is an extra mainspring that is either harder or softer than the one that's in there now. if you absolutly need to you may be able to boost the spring by stretching it with a couple pairs of pliers. or cut it (a little at a time) to lower velocity.
ok so now to complicate things even more. if you're using co2 (which i assume you are) and the co2 is too warm, the output pressure may be too high. the pressure of the co2 helps hold the valve closed, and if this pressure is too high, the valve may not be able to open enough. this can cause trracers to shoot very low velocities like the ones you describe.
the probelm? your co2 is too warm.
the solution? make it cold. the way i used to do this was dryfiring like 30 shots rapidly (autotrigger). also you can bleed the co2 tank somehow. or you can just throw it in a cooler with ice. remember, this may or may not be the probelm, you'll have to experiment.
my maverick velocity has always been very inconsistant.
phew, hope this helps
oh and i forgot to add, some people make detents by putting small strips of electrical tape on the inside of the gun... or so i've heard. i'd just do the folded piece of paper method.