Mp5k Semi auto firing

Syphen · February 4th, 2006, 09:09

Hey, Im sure this question has been asked before but I cannot find any info on it at all.

I got a TM Mp5k (ver 3 mechbox.. duh). Its a great little gun, bone stock never been opened before. Anyways, on full auto the gun never fails and works awesome.. semi auto is another story. If I shoot a couple shots in semi it will always lock up. Sometimes the trigger can still be pulled, other times it cannot, but the gun will not fire or move. I have to change to full auto and shoot then go back to semi. I know i've heard of this problem with guns if people rapidly fire on semi... but its happening even on NON rapid fire, its just a freak random thing that occurs VERY often, every 5-10 shots.

I was wondering if people have any idea what causes this and any possible solutions?

Thanks for the help in advance.

Greylocks · February 4th, 2006, 09:14

Usually, gear timing or selector plate adjustment.

CDN_Stalker · February 4th, 2006, 09:55

Something is out of whack. Greylocks, he said it's never been opened, so I'm not sure if it would be either of those, unless it did it to itself. Brings to mind the same problem with the team's G&P SPR. Recently it's been acting the same way on semi once in a while, locks up and won't fire, set it to full for a burst, then back to semi and all is good til next time. Really not sure, but am looking forward to figuring/learning what is wrong.

Syphen · February 6th, 2006, 22:33

So no for sure ideas yet?

mcguyver · February 6th, 2006, 23:09

I remember when I got my MP5K PDW a few years ago. It was set for safe and my sister was playing around with it and pulled on the trigger really hard, and it shifted the selector cam slightly (out of the groove that joins it to the selector plate) and it did the same thing. The only recourse I had was to tear the lower off and reset it back to it's proper position. It took some time as I didn't know anything about AEG's then, and I've had to do it again one other time after lending it out to a fellow at a game.

I think basically what happens is the selector plate never properly gets set to the semi position, thereby not applying the proper spring tension on the semi-auto release bar and giving you problems in trigger pulling. Full auto would just move that bar out of the loop, so to speak, and is easy to achieve even if the selector is not precisely in position. Semi-auto needs to be fairly precise as there now need to be interlocking done between the selector plate, the semi-auto bar and the sector gear.

beach_boy · February 6th, 2006, 23:49

What I've heard about this is, its quite a reoccuring problem with TM MP5's... my PDW does the same thing, and so does my SD6, I usually just play through it, so to make you feel any better, your not alone with this problem, thanks Mcguyver, I know now what to fix, or atleast try to..

Greylocks · February 7th, 2006, 06:41

I know he has not opened it, but I've seen the problem happen before (with time). It may be a matter of a slight misalignment at the factory, or that somehow it shifted.

Or it can simply be lack of familiarity with the quirks of trigger control.

I bet a slight timing problem is the cause. He should find an experienced local person to look at it.

Syphen · February 7th, 2006, 12:13

Quote:

Originally Posted by Greylocks

I know he has not opened it, but I've seen the problem happen before (with time). It may be a matter of a slight misalignment at the factory, or that somehow it shifted.

Or it can simply be lack of familiarity with the quirks of trigger control.

I bet a slight timing problem is the cause. He should find an experienced local person to look at it.

or.. how about you tell me how to fix it and I will fix it. k thanks :tup:

You talk like I am a freaking moron and new. I've just never worked on an AEG before, just lots of gbb's so far, I have no problem cracking open a gun as long as I know what to look for and fix.

Point_Man · February 7th, 2006, 13:13

I've been having the same issues working on a friends PDW. I'll assemble just the lower portion to ensure that it cycles both in semi and auto and it works fine. Then putting the entire gun back together it only fires semi. Sometimes it'll fire auto when the selector is 3/4 of the way to the auto setting. Definetly frustrating trying to figure out how to get it just right. In relation to my SD5...I've never had issues with the trigger nor the selector plate and switch. Odd for sure. Oh well...more tinkering ensues...

Greylocks · February 7th, 2006, 16:39

You did not ask for an exact solution; gear timing is described in the forums, so if you are not worried just reset that (look at the pictures in the guides).

First, just check if the selector plate moves as it should. It may be that simple.
Then check the selector plate contacts. So far that is all external to the mechbox.

Inside the mechbox, just follow the pictorial guides and make sure your shimming is ideal. That should fix the problem.

Sometimes this happens more often with a gun that has been worked on before and reassembled incorrectly. It's a bit tricky to align the selector button and the plate.

NuttyHunter · February 7th, 2006, 17:12

Point_Man is wrong. His SD5 has had some firing difficulties. I'm the one who plays with it though so he probably forgot that on the 28th of Jan I went to fire it in Semi and the trigger would not move. Moved it to full-nil. put it on safe. Took out Mag/ Sometimes the selector switch doesn't catch in Semi so I flipped it back to full then down into semi (safe to semi is when it acts up) and it worked withut the mag. I put the mag in and it didnt work. Flipped to full, it worked, then back to semi and it finally worked, but after 4 shots a bb finally lopped out, and on the 5th it was working fine. So... Point_Man's SD5 works 99% of the time. It just hates me.

I should mention that this was mid-game.

M

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February 4th, 2006, 09:09	#1
Syphen Trader rating Join Date: Jul 2004 Location: Orillia, Ont.	Mp5k Semi auto firing Hey, Im sure this question has been asked before but I cannot find any info on it at all. I got a TM Mp5k (ver 3 mechbox.. duh). Its a great little gun, bone stock never been opened before. Anyways, on full auto the gun never fails and works awesome.. semi auto is another story. If I shoot a couple shots in semi it will always lock up. Sometimes the trigger can still be pulled, other times it cannot, but the gun will not fire or move. I have to change to full auto and shoot then go back to semi. I know i've heard of this problem with guns if people rapidly fire on semi... but its happening even on NON rapid fire, its just a freak random thing that occurs VERY often, every 5-10 shots. I was wondering if people have any idea what causes this and any possible solutions? Thanks for the help in advance. __________________ Sponsored by Boland Howe: Cause Scheisse Happens www.bolandhowe.com

February 4th, 2006, 09:55	#3
CDN_Stalker Official ASC Bladesmith Trader rating Join Date: Jul 2003 Location: Ottawa, Ont.	Something is out of whack. Greylocks, he said it's never been opened, so I'm not sure if it would be either of those, unless it did it to itself. Brings to mind the same problem with the team's G&P SPR. Recently it's been acting the same way on semi once in a while, locks up and won't fire, set it to full for a burst, then back to semi and all is good til next time. Really not sure, but am looking forward to figuring/learning what is wrong. __________________ STKR Knives http://www.facebook.com/#!/pages/STK...17036668380871

February 6th, 2006, 22:33	#4
Syphen Trader rating Join Date: Jul 2004 Location: Orillia, Ont.	So no for sure ideas yet? __________________ Sponsored by Boland Howe: Cause Scheisse Happens www.bolandhowe.com

February 4th, 2006, 09:14	#2
Greylocks Trader rating Join Date: Dec 2001 Location: Gatineau, Quebec (Near Ottawa)	Usually, gear timing or selector plate adjustment.

February 6th, 2006, 23:09	#5
mcguyver Trader rating Join Date: Aug 2005 Location: Northern Alberta	I remember when I got my MP5K PDW a few years ago. It was set for safe and my sister was playing around with it and pulled on the trigger really hard, and it shifted the selector cam slightly (out of the groove that joins it to the selector plate) and it did the same thing. The only recourse I had was to tear the lower off and reset it back to it's proper position. It took some time as I didn't know anything about AEG's then, and I've had to do it again one other time after lending it out to a fellow at a game. I think basically what happens is the selector plate never properly gets set to the semi position, thereby not applying the proper spring tension on the semi-auto release bar and giving you problems in trigger pulling. Full auto would just move that bar out of the loop, so to speak, and is easy to achieve even if the selector is not precisely in position. Semi-auto needs to be fairly precise as there now need to be interlocking done between the selector plate, the semi-auto bar and the sector gear.

February 6th, 2006, 23:49	#6
beach_boy Trader rating Join Date: Jan 2005 Location: Prince George, BC	What I've heard about this is, its quite a reoccuring problem with TM MP5's... my PDW does the same thing, and so does my SD6, I usually just play through it, so to make you feel any better, your not alone with this problem, thanks Mcguyver, I know now what to fix, or atleast try to.. __________________ We'll do it like the Italian Job!

February 7th, 2006, 06:41	#7
Greylocks Trader rating Join Date: Dec 2001 Location: Gatineau, Quebec (Near Ottawa)	I know he has not opened it, but I've seen the problem happen before (with time). It may be a matter of a slight misalignment at the factory, or that somehow it shifted. Or it can simply be lack of familiarity with the quirks of trigger control. I bet a slight timing problem is the cause. He should find an experienced local person to look at it.

February 7th, 2006, 13:13	#9
Point_Man Trader rating Join Date: Dec 2001 Location: Ottawa, Ontario	I've been having the same issues working on a friends PDW. I'll assemble just the lower portion to ensure that it cycles both in semi and auto and it works fine. Then putting the entire gun back together it only fires semi. Sometimes it'll fire auto when the selector is 3/4 of the way to the auto setting. Definetly frustrating trying to figure out how to get it just right. In relation to my SD5...I've never had issues with the trigger nor the selector plate and switch. Odd for sure. Oh well...more tinkering ensues...

February 7th, 2006, 16:39	#10
Greylocks Trader rating Join Date: Dec 2001 Location: Gatineau, Quebec (Near Ottawa)	You did not ask for an exact solution; gear timing is described in the forums, so if you are not worried just reset that (look at the pictures in the guides). First, just check if the selector plate moves as it should. It may be that simple. Then check the selector plate contacts. So far that is all external to the mechbox. Inside the mechbox, just follow the pictorial guides and make sure your shimming is ideal. That should fix the problem. Sometimes this happens more often with a gun that has been worked on before and reassembled incorrectly. It's a bit tricky to align the selector button and the plate.

Mp5k Semi auto firing

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