Loss of FPS, After upgrades
 

Before upgrades on my G@G M4 I had a 375 fps.

I change
-SHS 7 tooth piston
-Prom piston Head
-Lonex cylinder
-ZCI Full Type 0 cylinder
-Lonex Nozzle
-Lonex 50 hop-up

After changing these Im getting 310fps with 0 hop-up, 120 with full hop-up.

Not sure whats going on.

I have great seals now, Not like before?

Please advise. Anything?

Chances are you need a ported cylinder, like the one you may have had. If you are over voluming, your cylinder has more air volume than the ideal for your barrel length, so the bb is out of the barrel before the piston reaches full speed, resulting in a lower FPS. If it's a regular M4 barrel length (14.5"/363mm) then you need a Type 1 ported cylinder.

Check and double check your air seal, if you are confident enough that you've perfected it and still having problems then check that t your piston is moving freely, if there is friction it will not return as fast causing low FPS. I've had similar issues with the SHS 7 metal tooth piston, will do a little more research to find the cause

Wrath, Good suggestion, But its the not ported for a 509mm barrel, Just like the stock cylinder.

Ron-E I think you might be on too something. I found the 7tooth too be a little bitchy for the piston head install.

I might switch back too the systema and check that.

Noticed the air nozzle gets stuck in the back position after firing.
I opened the gearbox and noticed the tappet plate stuck against the cylinder,
So I reseated it and tested it again, And again The tappet plate flexed and got stuck.

So ill order a new tappet plate, Then retest.

Are you putting back the spring for the tappet plate?http://i60.tinypic.com/6s5lxh.jpg

Good suggestion, But yes im putting the spring back.

The flex is when the sector gear spins, The tappetplate flexes too much and gets stuck on the piston.
http://imagizer.imageshack.us/v2/xq90/196/vdrp.png

I have this same problem in my King Arms M4
- Yes i attach the spring to both the tappet plate and the spot on the gearbox
- I put a new tappet plate in and it still happens, The nozzle does not spring back

Any guesses what this could be?

Thanks guys!

Very limited info online about this.

Its getting too be stupid. I put a brand new SHS tappetplate in, Same problem.,

Did you re-shim your gearbox or leave it as is?

I found this Vid on Youtube, The first half is the problem I have, Starting at 36sec. I don't have any misfeeding issues.
AND just too clear it up, I don't have that Ear splitting motor whine either LOL.
Airsoft AEG: Tappet Plate and Air Nozzle Troubleshoot - YouTube

sand the new tappet plate- it's too wide

The Stock plate work fine for years, Then stopped working, That is why I tried the SHS, And it does the same.

Can you post some pictures of what the gearbox looks like all put together and also how it ends up when you try and cycle it?? That would help a lot

After assembling the gearbox, you should be able to push the tappet plate back and forth.

Just to add to this, because I know alot of people make the mistake of testing the movement on all their parts without screws or atleast pressure on the two halves of the mechbox. You need to test the movement with screws holding the two halves together and test both the piston movement, and the tappet plate.

As Stealth said, after the mechbox is assembled and screwed together, push the nozzle in and out, if its got any resistance at all, fine grit sand it until it moves in its grooves smoothly, add a little grease.
Do the same thing, only without a spring and gears and such, with the piston, move it back all the way and forward and test for resistance.

When i was putting the mechbox back together it worked fine, once i shot on semi auto that's when the nozzle got stuck, after a few shots on full auto is would go back to being able to be pressed in and it springs back, then semi again and it gets stuck... so on so forth.

if and when i take it back apart i will take pictures of it , i just saw this thread and figured id post about it too

Thanks guys

Ill try too make a video this weekend.

Mine does 100% the same as Bahhwa.



Renegade), The Gearbox is 100% back together and tight.

Stealth, I have 100% free movement of the nozzle when first assembled, As soon as I pull the trigger, The nozzle gets stuck in the back position.
If I try Auto, After a few pulls, The nozzle will free up and move as normal, until I pull the trigger again.

I think the sector gear is still engaged on the piston causing this. Ill redo my AOE. 1:00 is not working on this gear box.

so you fire a shot in semi. the nozzle gets locked back.
if you just tap the trigger light enough to move the gears around a bit, can you pull the nozzle out by hand and gage the resistance?
Also, whatever the nozzle/tappet plate does when the sector gear catches it, is exactly what it does when you move it back and forth by hand to make sure it's free. So if the sector gears makes it catch on something on the way back, you should be able to replicate that just by pushing the nozzle back

Isn't it pretty normal for the nozzle to stop in the rear position when firing in semi

If the nozzle feels "stuck" when it's in the rear position that's because the tappet plate is already up against the cylinder head and the sector gear has pulled the tappet plate back. It's not actually "stuck".

That's the first thing I thought too, I just assumed he knows that and the nozzles actually getting caught up on something lol

Ok You guys are on the money, I think :)
It semi, The nozzle Stops in the Back position, And is not able too move forward by hand. Is this the proper function?

As for it getting stuck in the back position, I assumed this was not correct due too my 60 FPS loss after all my upgrades.

Ive double and triple check compression on the cylinder all the way too the nozzle. Im not able too push the piston with my finger blocking the nozzle, in Easy at all.

So if all else is normal, My last possible issues could be. The nozzle does not fit right?
OR The Nozzle isn't meeting the hop-up properly?

I guess Ill take it apart and check this issues too.
Please keep the help coming.

Try with hop up on a lower setting.
M120 should net you 440-450 FPS if you have a good air seal, not 310. Only one of my guns runs a M120 and it shoots 455 FPS.

I've also seen serious fps drops if the hop is all the way off, a BB gets loaded and the force of the air nozzle moves it PAST the hopup, and results in extremely low fps.

After rebuilding the full system again Im back too normal.
Im at 385FPS On the stock spring. My Old G@G motor just cant pull the M120.
Even at 385FPS, My RPS is a low 10.5.
This is a M4 DMR, So Auto fire is unlikely.

If I added a New motor and M120 Spring, This gun would be un-field able I think.

As for the problem, PURE Noob shit. I had the Main spring backward, And my AOE was out a bit.

:banghead::banghead::banghead:

Learning as im going :)

nice.
What about a tienly or lonex motor?
Also what kind of battery are you using?

Im thinking a lonex Just because I like too Order From AirsoftStore Canada

And the Batt is a 9.6 1600.

Not sure how much more I want too dump into this gun, Its not even my main LOL.

Still Very fun too build and learn.

I have $1000 invested in a gun I haven't gamed in a year and a half lol

Glad it works now, but neither of those would contribute to a real fps drop

having a non-linear spring backwards has been known to make anywhere from 30-60fps drops
Don't ask me to explain it, I don't understand the science

I've heard that too, but I've never noticed a difference. Back in my noob days I installed a M100 backwards and still got 405 FPS out of it. Doesn't make logical sense to me.

Yeah well short widebores producing better range and accuracy than long tightbores doesn't make logical sense to most people either lol