Help!!! Problem with 2 Ver 2 Gearboxes

[Hellbringer]

Hi,
I did a upgrade to a GR-25 and that did some matenece to my M4 and they are both having the same symptoms and i dont know what is wrong

symptoms are that i have low FPS my m4 has a m100 spring with systema gears. i started to have a problem with the selector plate so i tore it down to replace the selector plate and i found that the gearbox was cracked. so... and i found tha the internals where dirty and taking a tole on the internals so i ordered a new guarder gearbox, guarder cylinder enhancement set (has cylinder, piston, and piston head), metal spring guide, new bearings and a madbull ver2 tight bore barrel. so i built the the GB and i have low FPS the gun before i tore it down was shooting 350-360 and now it is 195-200 any suggestions

now the GR-25 this one is kinda the same think but a little different. bought the GR-25 and it didnt have enought FPS so i bought a guarder sp150 full tune up kit, guarder GB and madbull ver2 tightbore barrel. built the gun up and i get 320-330fps when the sp150 spring should be 490-520.

do you guys have any suggestion on what is wrong?

Thanks
Mike

[Styrak]

Did you grease the cylinder?
Did you test the compression on the cylinder?

[Hellbringer]

i greased the piston o ring, and i dont know how to test the compression neccessorly but if you plug the nozzel i cen get a suction and compression under my finger. is it enought i dont know

thanks mike

Originally Posted by Styrak

Did you grease the cylinder?
Did you test the compression on the cylinder?

[Shirley]

Did you connect the tapplet plate to the nozzle? I tend to forget about the tapplet plate. lol

[Skladfin]

you might have installed the spring backwards

[damage]

Gearbox to hop up has an alignment issue. You said "GR-25" and thats a G&G am I right?. Some G&G metal receivers just dont accept aftermarket gearboxes straight up. Minor modification inside the receiver is required or the best solution is get another G&G gearbox.

[Hellbringer]

ok a little update.... i found something that i have fixed and i am on the right track but i am still having problem....

first off i changed the cylinder and the cylinder head and i learned that you cant do that the cylinader head is different and a normal version 2 cylinder head. so i changed the cylinder and the cylinder head back and it helps some but it sounded like crap and droppd my fps lower to about 280. so thinking that it is the old cylinder hear i bought a new one (systema Area 1000) and i also changed the hop-up bucking to guarder 170% bucking and retesting and i am getting 390-399.

now for the question portion.

1. when i pressure test the cylinder/piston without the nozzle it works great and there is no air leaking. when i put on the nozzle with the air leaks around the base back toward the cylinder head. is that normal?

2. the cylinder sleeve that comes with the GR-25 is not ported at all. will installing a ported cylinder help? (i have one from my TM m4)

3. with these upgrades where should it be shooting?

Guarder Torque up gears
Guarder metal Spring Guide
Grauder SP150 Spring
Guarder Polycarb Piston
Systema Area 1000 Polycarb piston head
Stock G&G Cylinder
Stock G&G Cylinder Head
Guarder Tappet Plate
Guarder 170% hop-up bucking (turned off while chrono)
650mm Madbull Ver 2 Tight Bore Barrel

Thanks Again Mike

[Skladfin]

keep the unported cylinder.

also, I don't think there's anything wrong with the gearbox, It's very likely that it's a hop up to mechbox airseal problem

[DarkAgent]

did you shim correctly?

does it make alot or extra noise when it cycles?

[Hellbringer]

no it dosnt make any weird noise but how whould the gears not being shimed lower the FPS?

thanks mike

[ThunderCactus]

Did you over grease the piston head?
I don't even use grease, I use a light oil for the piston head, grease is too thick.

[Hellbringer]

i used G&P cylinder grease. i did put a good amount on though.????

Thanks Mike