systema bore up kit for m16

[mimozine]

hi guys, have bought one of these kits. got it out for a gander. anyway cylinder head fits perfectly and i attached a piston to piston head. thing is the o-ring on piston head seems very loose to me, not sure if thats how its meant to be? only cracked a g36 v2 gearbox before to change a spring so could do with some advice.

also tried blocking end of cylinder and putting piston into it to check compression. there is a slight resistance but not sure how much there should be? haven't applied grease to it yet, i take it that will improve seal?

 

[mimozine]

should i put something underneath the o-ring on piston head, so it cant move about so much?

 

[Samurai]

It should be loose. That's how O rings work. Pressure builds on one side that expands it and it seals against the cylinder.

Apply a tiny amount of silicone grease to the cylinder.

 

[mimozine]

well its good that its as it should be, cant say i understand it however. not got any silicon grease but i got some guarder teflon grease thats says its good for cylinders and gearbox?

 

[Iceni]

Worst thing that will happen is the grease might make the o-ring brittle over time or it'll wear out faster. When this happens you'll loose compression and have to replace the o-ring. It's not something to worry about if you know how to strip and rebuild your gearbox. I use whatever grease I have to hand O-rings are cheap, And it's an excuse to open the box and check for wear.

Price wise even the branded o-rings are cheap. If in doubt you can always go to a bearing and seals merchant they should be able to supply various grades of ring to the same spec. Including some really nice coated ones that are totally unnecessary like PTFE Encapsulated O-Rings.

The G36 is generally a version 3 gearbox as well. Not version 2 like you posted. Version 3's are really robust boxes and really easy to work on. There also pretty cheap to buy a complete box for if you want or need a new one.

Now that you have it open do a full checkup on the box.

If it has nylon gear bushings now is the time to upgrade to metal ones and shim the gears. There are a few sizes of bushings 6, 7, 8, 9mm so measure one and get the correct size.

It's also a good time to be thinking about a mosfet if you run lipos. You can upgrade to a mosfet without needing to open the gearbox IF you can solder. It's one of the advantages of V3. It'll stop your contacts arcing, and greatly decrease the chance of getting fire problems through burnt out connectors. If you can't solder then a few companies do a basic kit that can be dropped into an open gearbox.

http://www.evike.com/products/38281/

https://www.amazon.co.uk/SHS-PISTON-HEAD-O-RING-AIRSOFT/dp/B00DS3YYBC