G&P URX III CQB - reccomended piston upgrades

[Guyver1]

Morning all,

 

Looking for a steer on which is the best/compatible piston and cylinder head for my G&P URX III CQB.

 

Specs copied from the landwarrior site

http://www.landwarriorairsoft.com/airsoft-rifles-c38/electric-rifles-c45/g-p-urx-iii-cqb-p1831

 

It has:

• Gearbox Type3 8mm Bearing 
• AEG Motor G&P M120 Hi-Speed

 

Not having any major issues, but the FPS had dropped quite a bit from new down to 310 from 360.

I think it needs to be opened up and given a bit of TLC and I thought i'd give it a new piston and cylinder head whilst it was open.

 

Any reccomendations appreciated.

 

TIA

alan

[Katana]

The gearbox is a version 2 and not a version 3. Land warrior goofed on that one. You don't need any new parts, you need maintenance. It literally needs fresh silicone rub down and possibly some new o-rings around the cylinder head. Whilst you are inside the gun, give it a fresh shim job. Just remember that springs wear in and 360fps was your spring before you broke it in. All springs will drop fps after about 1000+ rounds. 

 

Re-shim

Re-lube

Fresh o-rings if needed

If you really want to, get a high torque motor to replace the high speed one. Your trigger response will drastically improve but your ROF will go down. It's not really needed though but the G&P M120 motor does suck balls. If it is leaking from the cylinder head, a wrap of teflon tape around it before you put it in the cylinder should be all you need. DO NOT PUT TOO MUCH ON. You will create a weak point in your gearbox and f*ck it so you only need enough. Just watch this video: 

 

[Katana]

If you haven't shimmed before, you may want to watch this one too: 

 

[Guyver1]

brilliant.

 

Thank you for taking the time to reply.

Very, very  useful information.

 

 

[Hangtight]

The only thing about the G&P 120 motor that isn't much cop is the magnets. Is actually a very well built 16TPA motor, just with weak ferrite magnets. Get yourself some of these...

 

http://www.firestormsystems.com/shop/gearbox-parts/custom-n52-aeg-motor-magnets.html

 

And you've got a motor that has the performance of an SHS Hi torque, and nearly the refinement of an ASG CNC 30K. It'll give you a much snappier trigger response.

If you don't want to pull a motor apart then both the SHS HT, Rocket Airsoft balanced and ASG CNC 30K are effectively the same motor you have, but with much more powerful magnets and hence a higher torque, so you'll get the same rate of fire, better trigger response and a lower current draw from your battery

 

G&P Air seal components are already excellent. Your gearbox will have an aluminium cylinder head and an aluminium air nozzle fitted with an O ring seal. Disassemble, clean and lubricate. Replace any O rings as necessary. The one air seal component that might need replacing is the hop rubber. The piston is OK, but check the plastic teeth for wear. If you think it needs replacing then get an ICS POM piston and  head. Great bit of kit and tough as old boots.

If you find you do need O rings go and get a selection box from the plumbers merchants. A fiver will buy you more than you'll ever need in a range of sizes.

[Guyver1]

Good news on my pocket. that i don;t need to be spending on it apart from time.

 

Motor info is good to know.

 

thanks for the info Hangtight , much appreciated.