KWA M4 hop-up problem

AR-Mad

I have a KWA M4 RIS 2GX version and the hop-up rubber doesn't work. This AEG has the bucking where it looks liike two pins are protruding and it doesn't put any spin on the BBs. All the BBs start dropping after 5m. The AEG is sub 1 joule and i have read that the KWA bucking only works on AEGs with <380fps. Any help welcomed. Thanks

T4RGET

AR-Mad wrote: »

I have a KWA M4 RIS 2GX version and the hop-up rubber doesn't work. This AEG has the bucking where it looks liike two pins are protruding and it doesn't put any spin on the BBs. All the BBs start dropping after 5m. The AEG is sub 1 joule and i have read that the KWA bucking only works on AEGs with <380fps. Any help welcomed. Thanks

unless it's something in the design I can't see how the hop up will only work above our limit, it makes no sense. Have you taken the hop up unit apart? the parts could just be worn/damaged.

AR-Mad

i know its confusing. I have taken it apart and it looks fine. The hop-up is accurate but offers terrible range. When i switched to a regular bucking my M4 started flying those BBs.

T4RGET

AR-Mad wrote: »

i know its confusing. I have taken it apart and it looks fine. The hop-up is accurate but offers terrible range. When i switched to a regular bucking my M4 started flying those BBs.

hmm very strange, I have little experience with KWA hops, and don't really remember too much of them, none of the insides are broken are they? sometimes the two pins that hold the nub in snap but they look okay..

AR-Mad

everything is fine. I doubled checked aswell. the hop-up arm pushes the bucking and it shows the shape. the design is like the H-nubs but flappier. its like the BBs just slip past the bucking rather than being spun by it.

T4RGET

AR-Mad wrote: »

everything is fine. I doubled checked aswell. the hop-up arm pushes the bucking and it shows the shape. the design is like the H-nubs but flappier. its like the BBs just slip past the bucking rather than being spun by it.

that's odd especially seeing the H-hop design, have you tried a different hop chamber? it may be awkward but try hold a standard chamber and barrel up to the gearbox as KWA are two part chambers aren't they?

Southern Dandy

Hey AR-MAD, The kwa hop-up rubber is generally for aegs with a higher fps your talking 400fps+, its design (the two teeth) is based on the firefly rubber. A drop at 5 metres is seriously odd though.

I put up a similar post T4RGET may remember with my KWA rubber giving poor range. I tried a MADBULL and it made it worse, i then opted for the prometheus pink rubber and nub and my god the difference, hitting a relatively small target at 40m wit zero adjustment of my aim using .25g bb's with a very light wind. Would defo recommend it.

Southern Dandy

T4RGET wrote: »

that's odd especially seeing the H-hop design, have you tried a different hop chamber? it may be awkward but try hold a standard chamber and barrel up to the gearbox as KWA are two part chambers aren't they?

They are and are a balls to source, only seen them in US websites. You can mod the lower receiver for after market chamber but more hassle than its worth.

GreenCarver

My KWA M4 lacked in range with the stock hop rubber but I threw in a ultimate one and the range almost doubled

AR-Mad

To SouthernDandy and GreenCarver, i agree. I am going to buy the prometheus bucking but before i do i tested with a regular AEG bucking from a Cyma M4 and i am not kidding i saw my range fly to beyond 20 metres. haven't tested it fully and with your observations it confirmed that the KWA bucking doesn't work with 1j AEGs. thanks for the help. glad to know i wasn't the only one with this problem. Also the KWA does get credit for excellent consistancy and accuracy to make for its absence in range.

Southern Dandy

AR-Mad wrote: »

To SouthernDandy and GreenCarver, i agree. I am going to buy the prometheus bucking but before i do i tested with a regular AEG bucking from a Cyma M4 and i am not kidding i saw my range fly to beyond 20 metres. haven't tested it fully and with your observations it confirmed that the KWA bucking doesn't work with 1j AEGs. thanks for the help. glad to know i wasn't the only one with this problem. Also the KWA does get credit for excellent consistancy and accuracy to make for its absence in range.

It would be good if KWA released a softer rubber for aeg's shooting below 400fps, but they are huge in America where fps is near light speed in some places so why bother making softer rubbers for us 1joule peeps. But once you get them going they are excellent aegs, gearbox is top quality only gripe would be the proprietary hop-up chamber and air nozzle.

On a side note you may have to trim the new hop up rubber a bit off the end it wont pop straight in there, and avoid silicone oil if possible on it (well i honestly dont know if the prometheus pink would be affected by oil), some rubbers are really effected by that oil particularly guarder clears.

AR-Mad

grand. thanks for the tip.

Kristov

If you want you could fit a TM unit to the KWA their basicaly the same ..but you will have to fit an Stock M4 air nozzle too ..

Ive done this to quite a few Kwa M4s and have had no trouble ..

Their is alot of work involved fitting a one peice hop unit to Kwa`s i done it once but replaced the original after not too long ..