Modify Cylinder set on an MP5

Batchokookies · February 24th, 2009, 19:16

Hey I've been having some problems installing a modify cylinder set on my MP5. I've reshimmed everything, greased it all and basically done everything to the best of my ability. unfortunately every time I test it the piston seizes halfway back and nothing will move. I've installed it 3 times just to make sure i've done it correctly but it still seizes. any help? and has anyone had any problems with this set before?

If it helps, the set came with a new piston, cylinder, cylinder head and nozzle.

Thanks in advance!

coach · February 24th, 2009, 19:17

have you fully charged your battery?

Batchokookies · February 24th, 2009, 19:19

Quote:

Originally Posted by coachster

have you fully charged your battery?

yep. i've tried 3 different fully charged batteries.

Big Pepa · February 24th, 2009, 19:35

This is my first post here so Hi everyone!! I'm a Canadian living in Japan and this is the most useful forum ever... anyway....

Your problem sounds strange. Are you sure you shimmed the box properly? when you put the gearbox back together did you loosen an electrical wire?

It sounds like your motor is not strong enough to pull the spring. I assume you are running a stock EG700. Motor power should not be a problem unless you are running a crazy strong spring - and even then.... I'd recheck the shimming... there are some great shimming guides on this website.

I have the same problem with a pistol of mine... but only when I put in a stronger spring. My pistol motor is by no means an EG700 though.

F34N0R · February 24th, 2009, 20:01

If batteries are fully charged and doesnt work, I suspect gear shimming

Donster · February 24th, 2009, 20:18

are the gears aligned and meshed properly by any chance?

Batchokookies · February 24th, 2009, 21:11

Quote:

Originally Posted by DONSTER 125

are the gears aligned and meshed properly by any chance?

well i guess since everyone is saying shimming, i guess i'll check the shimming one more time. and i'll check the gear timing too. you mean i should take some shims off though, right?

Batchokookies · February 24th, 2009, 21:13

Quote:

Originally Posted by Big Pepa

This is my first post here so Hi everyone!! I'm a Canadian living in Japan and this is the most useful forum ever... anyway....

Your problem sounds strange. Are you sure you shimmed the box properly? when you put the gearbox back together did you loosen an electrical wire?

It sounds like your motor is not strong enough to pull the spring. I assume you are running a stock EG700. Motor power should not be a problem unless you are running a crazy strong spring - and even then.... I'd recheck the shimming... there are some great shimming guides on this website.

I have the same problem with a pistol of mine... but only when I put in a stronger spring. My pistol motor is by no means an EG700 though.

I'm running the CA high-torque. no upgrade spring. electricals seem fine, shims might be the problem. thanks! i'll report once i reshim.

CDN_Stalker · February 24th, 2009, 21:21

Try it with the stock spring guide. I've had Deep Fire pistons lock fully back due to a bearing spring guide, but never a Modify piston. Also, sounds like your cylinder head/piston head is pressing the piston back a bit too much and is casuing the gears to grab the wrong tooth of the piston, making it jam back. Is a common problem sometimes when the piston sits back a bit too far. So take out the tappet plate, and with no spring manually turn the gears and watch where the sector gear first tooth grabs the piston. And put the old piston back in to see if any difference. Helps to compare old piston head and piston to the new set, sometimes they are made a bit longer, which is what causes the problems.

Nutshell, your shimming is likely fine, and no way will it be the problem. And timing can't be changed, is the way the mechbox is designed as far as all internals goes. It's not adjustable as some people think it is.

Batchokookies · February 24th, 2009, 22:07

Hey thanks for all your help guys it was just the shimming. now that i've solved that problem, I'm looking for a spring that my current motor can handle and will get me up to the 390 fps range. my current upgrades are the cylinder set, madbull 300mm 6.03 tightbore and i'm now running a 8.4V 3800mah large battery. any suggestions?

CDN_Stalker · February 24th, 2009, 22:53

Modify 100 spring should get you close, and you can't get much more consistant than that, more so due to the cheap price. Might net you around 370fps, gives you better perfoemance at that fps and more headroom. I've downgraded guns because they were close to 400fps and performed like ass.

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February 24th, 2009, 19:16	#1
Batchokookies Trader rating Join Date: Jul 2008 Location: Calgary	Modify Cylinder set on an MP5 Hey I've been having some problems installing a modify cylinder set on my MP5. I've reshimmed everything, greased it all and basically done everything to the best of my ability. unfortunately every time I test it the piston seizes halfway back and nothing will move. I've installed it 3 times just to make sure i've done it correctly but it still seizes. any help? and has anyone had any problems with this set before? If it helps, the set came with a new piston, cylinder, cylinder head and nozzle. Thanks in advance! __________________ WE SCAR TM M14 RWC G18C KWA P226 PTP X2 VFC/UMAREX MP5A2

February 24th, 2009, 19:35	#4
Big Pepa Trader rating Join Date: Feb 2009 Location: Japan	This is my first post here so Hi everyone!! I'm a Canadian living in Japan and this is the most useful forum ever... anyway.... Your problem sounds strange. Are you sure you shimmed the box properly? when you put the gearbox back together did you loosen an electrical wire? It sounds like your motor is not strong enough to pull the spring. I assume you are running a stock EG700. Motor power should not be a problem unless you are running a crazy strong spring - and even then.... I'd recheck the shimming... there are some great shimming guides on this website. I have the same problem with a pistol of mine... but only when I put in a stronger spring. My pistol motor is by no means an EG700 though. Last edited by Big Pepa; February 24th, 2009 at 19:43..

February 24th, 2009, 20:01	#5
F34N0R Trader rating Join Date: Jun 2003 Location: Saint-Georges, QC	If batteries are fully charged and doesnt work, I suspect gear shimming __________________ WAR-THUG CORP.

February 24th, 2009, 19:17	#2
coach aka coachster Trader rating Join Date: Mar 2008 Location: T dot	have you fully charged your battery?

February 24th, 2009, 20:18	#6
Donster Trader rating Join Date: Jul 2007 Location: GTA	are the gears aligned and meshed properly by any chance?

February 24th, 2009, 21:21	#9
CDN_Stalker Official ASC Bladesmith Trader rating Join Date: Jul 2003 Location: Ottawa, Ont.	Try it with the stock spring guide. I've had Deep Fire pistons lock fully back due to a bearing spring guide, but never a Modify piston. Also, sounds like your cylinder head/piston head is pressing the piston back a bit too much and is casuing the gears to grab the wrong tooth of the piston, making it jam back. Is a common problem sometimes when the piston sits back a bit too far. So take out the tappet plate, and with no spring manually turn the gears and watch where the sector gear first tooth grabs the piston. And put the old piston back in to see if any difference. Helps to compare old piston head and piston to the new set, sometimes they are made a bit longer, which is what causes the problems. Nutshell, your shimming is likely fine, and no way will it be the problem. And timing can't be changed, is the way the mechbox is designed as far as all internals goes. It's not adjustable as some people think it is. __________________ STKR Knives http://www.facebook.com/#!/pages/STK...17036668380871

February 24th, 2009, 22:07	#10
Batchokookies Trader rating Join Date: Jul 2008 Location: Calgary	Hey thanks for all your help guys it was just the shimming. now that i've solved that problem, I'm looking for a spring that my current motor can handle and will get me up to the 390 fps range. my current upgrades are the cylinder set, madbull 300mm 6.03 tightbore and i'm now running a 8.4V 3800mah large battery. any suggestions? __________________ WE SCAR TM M14 RWC G18C KWA P226 PTP X2 VFC/UMAREX MP5A2

February 24th, 2009, 22:53	#11
CDN_Stalker Official ASC Bladesmith Trader rating Join Date: Jul 2003 Location: Ottawa, Ont.	Modify 100 spring should get you close, and you can't get much more consistant than that, more so due to the cheap price. Might net you around 370fps, gives you better perfoemance at that fps and more headroom. I've downgraded guns because they were close to 400fps and performed like ass. __________________ STKR Knives http://www.facebook.com/#!/pages/STK...17036668380871

Modify Cylinder set on an MP5

Upgrades & Modifications