Bearing Piston head/spring install..... issues!

[Janz99]

I started to install my new bearing piston head and bearing spring guide, but i have a couple questions. I havnt decieded if im going to put my new spring in yet, or if im going to re-use the stock spring. The problem i have, is that the factory spring has a small hook on the end of it that wont seat on the back side of the piston head. Can this just be trimmed off to seat properly?

Thanks
Ryan

[Amos]

It would be best to purchase a new spring, Stock marui springs should still give you a fairly consistent reading, but without the hook and "block" your results may not be as consistent as they can be.

If you want to stay under the 350 FPS level, I'd reccomend a modify S90+ spring from www.airsoftparts.ca

[Janz99]

I have a modify s120 here, but im hesistant to put it in. Im not sure i want to grenade the gear box just yet. I guess ill have to order another spring and a re-shim kit.

Id like to try and keep the gun where it is (370-380fps). Any recomendations on springs?

Thanks
Ryan

[m102404]

with a bearing spring guide, a Modify S100 will probably put you there. A lot of other factors affect it.

A S110 might put you just over 400fps with other upgrades installed and a tight setup....so if you want to be safely under limits (not sure what yours are) go one step down.

The diameter of some springs are just a hair too big for some bearing plates on spring guides. It's hard to notice this until the spring is under load (i.e. trying a shot). The piston body will jam/bind the end coils of the spring on the bearing spring guide....essentially locking the piston. Depending on the body it can be a bugger to get apart at this point as well.

Hedge your bets and stick with the same manufacturer for the spring guide/spring.

Best of luck,

Tys

[Janz99]

Originally Posted by m102404

with a bearing spring guide, a Modify S100 will probably put you there. A lot of other factors affect it.

A S110 might put you just over 400fps with other upgrades installed and a tight setup....so if you want to be safely under limits (not sure what yours are) go one step down.

The diameter of some springs are just a hair too big for some bearing plates on spring guides. It's hard to notice this until the spring is under load (i.e. trying a shot). The piston body will jam/bind the end coils of the spring on the bearing spring guide....essentially locking the piston. Depending on the body it can be a bugger to get apart at this point as well.

Hedge your bets and stick with the same manufacturer for the spring guide/spring.

Best of luck,

Tys

The limit here for outdoors is 425, and 350 for indoors. I ended up ordering a modify s110 spring, shim kit and a new modify air nozzle. Mod list so far is:

-modify bearing spring guide, bearing pistion head, air nozzle and s110 spring, and a madbull tight bore barrel. I also ordered a new hop up rubber.

Ill be re-shimming the gear box, cleaning and assembling everything. Hopefully this will be keep the gun reliable and accurate.

Thanks for the advice guys!

Ryan

[Janz99]

I made a post in the gun doc section, but i thought i would post it here to:

I have a DPMS m4. I currently just did the following upgrades:

-modifty s110 and s120 spring
-modify bearing spring guide, and polycarb. bearing piston
-modify air nozzle
-guarder hop up robber
-complete re-shim

So ive taken apart the gun twice now, the first time i re-shimed, put in the above parts with the s120 spring. I tried it for the first time, and the gun compresses the spring about 1/2 way, then stops. Pull the trigger in both auto and semi auto and all you here is CLICK. Its almost like the gun is jammed, or just can't compress the stiffer spring any further then half way.

I thought it was just to stick of a spring, so i took the whole thing apart again, re-checked the shim job (everything looked fine) and then put in the 110 spring. I put it all back together and it did the exact same thing. It compresses the spring half way then stops/siezes and all you hear is click now everytime you press the trigger.

Is this an issue of the motor just doesnt have the torque to turn it over completly? Or is there something else going on here?

Thanks
Ryan

[ujiro]

Yeah the DPMS stock motor won't have much luck drawing such a stiff spring back. Try putting a softer spring in, or buying a better motor.

[Janz99]

Just thought id update this incase anyone searches for this later on down the road. I ended up putting the stock spring back in and it worked fine. Seems as though the factory motor just cant handle the Modify s110's or s120's.

Ryan