Where can I find a drive spring to replace the Tippmann model 98 low pressure systems spring.

My gun won't shoot past 250 fps and i believe the spring is the problem.

This spring is larger than any found in the standard replacement kits (because the bolt comes out the rear of the gun).

The bolt comes out the rear on this low pressure kit and the kit was install by the tippmann factory, the kit is about 5 years old, but still looks like what is still being sold from tippmann.

Thanks

Paul

Probably the spring.  Prepare for flaming because you stickied this.

Nobody flame him this is his first post.

I cranked the reg. up to 650psi and it still shot 250 fps. (with the low pressure kit the gun should run between 300-400 psi). When the reg. is at 400 psi the gun shots 250 fps.

I was told that tippmann rely a lot on the spring to help with ball velocity and that seems to be the case here.

I am pretty certain it is the spring, but I can't find a replacement.

I could not find any part numbers to order a replacement and I looked at the cut sheets from tippmann on the install of the low pressure system - but it does not give any part replacement numbers.

This low pressure system (I was told by previous owner) was installed by Tippmann (gun was sent to them and had response trigger and low pressure installed).

I have been at a couple of places in MA. and no one is really familiar with this low pressure system (Ithought that was kind of odd since it is a Tippmann modification).

I have done both to the velocity screw , out to increase, in to decrease.

I have chronographed,with both my chrono and the fields and came up with the same results.

That is why I thought it might be the drive spring.

Any idea on where I might find a spring for the low pressure system?

PaulB wrote: I have done both to the velocity screw , out to increase, in to decrease. I have chronographed,with both my chrono and the fields and came up with the same results. That is why I thought it might be the drive spring. Any idea on where I might find a spring for the low pressure system?

Let's see if we can figure this out. When you speak of the drive spring I assume that you mean the spring that drives the hammer forward to strike the power valve pin. If my assumption is correct then you might find you can place a spacer in the center hole of the cap so that the guide pin, with the spring, is pushed towards the hammer. This causes the spring to exert more pressure on the hammer. A spacer can be something like a BB or a plastic bead from a hook rig like you'd find in a fishing gear store. You also might try pulling the spring gently to stretch it some.

But, easiest thing to do is call Tippmann. Knowing the way they do things, they will probably send you a new spring.

Oops! I had forgotten that this set up uses a rear cocking knob. I find it hard to believe that there is no straight forward way to dis-assemble the hammer/spring/back cap assembly. Can you give more detail?

FyreFly wrote:   You can't replace just the spring, you would need an entire new rear bolt assembly. Since the bolt cannot (reasonably) be seperated from the rear cocking knob.

So you are saying that the back cap, the spring, the guide rod and the bolt on the LPK are an inseparable assembly? Are you sure the cocking knob does not unscrew from the rod?

The rod will actually unscrew so you can replace the spring.

If you look at the last 5/8" of the rod (the part that is sticking out of the gun) where it starts to flare out you will actually see a fine line around the the shaft.  It has lock tite on it but that flared part will unscrew from the back of the rod gaining access to replace the spring.

As far as the cocking rod being glued in I am not sure but it would make sense or at least it was pressed in and fastened- glued somehow.

I did not stretch the spring since I figured that it would give eradict performance and it will just compress with time and I would have the same problem.

I e mailed Tippmann 3 days ago and got no response so I will call them for a replacement spring.

I am suprised at how few people have seen the low pressure system from Tippmann.

I have been to two different fields and my set up is the first they have seen.

Thanks for the interest and the help, when I receive the spring I will see if it solves my velocity problem.

To unscrew the flared end I:

When i unscrewed the flared part on the rod I put the end (the flared part) in a bench vise with card board on each side (against the vise jaws so as not to mar the rod) and twisted, it was hard to turn but it did start to spin - but it has lock tite on it so it is not easy to do.

The rod did not come out of the rear bolt.  The end of the rod unscrewed form the rest of the rod.

It would be nice for tippmann to mention this in their installation instructions so people aren't out buying the whole assembly.

Paul

yeah but I had premium grade cardboard - I think it was from a six pack.

Bottom line metal on metal will cause major burrs, and are the rods aluminum? Kind of softer than the hardened jaws of a vice.