mp5 hop up lever issues.

[boris the pict]

Hi guys,

 

I've done a couple of searches but came up blank so i'll ask you guys.

 

Every time i set the hop on my mp5 the first bb down the pipe pushes the whole thing back to 'neutral' what can i / should i do?

 

cheers

 

Boris.

[shinhk]

is it loose? what brand is it? make sure all the screws are tightened, put loctite if necessary. The First Factory strike chamber might help solve the problem. But if you don't want to spend the money then there was a way to make it more tight by using tape and washers or something (not sure what it was that someone else did on the forum).

[Tom Andrews]

On the end of the hop up lever spindle should be a small O ring. This retains the hop lever and provides friction to stop it moving.

[shinhk]

if you're talking about that small little o-ring that's on the other end of the lever it's just there to hold the lever in place. it doesn't really give much friction at all. i know becasue i don't have that o-ring on one of my mp5's running with the stock hop-up and i don't have the problem the OP does. I took it off because it broke since it was old. But the hop-up is still running fine w/o resetting problems even after 10-years. Then again, that gun is shooting at 1joule and i'm not sure what power the OP is shooting at.

[epicdoom]

I remove the gears from my hop up and install small O-Rings behind the gears. These will go directly between the gears and the hop up body I put a small drop of loc-tite on the spring clips to hold it togeather tightly. I can take some pics if it tomorrow if you like, so you can see how I do it. I havent had a hop up reset in a long time.

 

 

Doom

[epicdoom]

Ok I didnt want to rip my MP5 apart to show this I needed to do it to my M4 same basic idea You will need 3 O-Rings some loc-tite and some Ca glue AKA (crazy glue) and some sand paper or a nail file.

Gun and hop up unit dissasembled and parts layed out

Close up of the parts needed

First thing you need to do is get the smallest and thinest o-rings you can find for the selector gear and the intermediate gear. The size i found and use is 006-N70 Part # 9I1496 rub them on a piece of sand paper or a nail file to get them thin approx. .7mm now install them in the location noted in the pic below.

Next we need to get a little bit larger o-ring for the cam gear size i used is 110-N70 Part# 9I2341 file this one down also to .7mm install it onto the cam gear and put a very small drop of CA glue on it to hold it in place on the gear. pic below shows it installed.

now that we have this done install the intermediate gear and put the little lock ring on the shaft. Then install the Cam gear and put the lock ring in place. Install the selector gear and install the screw with a tiny drop of loc-tite on the threads. Now look at the gear mesh from the angle in the pic below. Make sure the gears mesh good, you can adjust this by pushing the lock rings on tighter. Once you have the mesh correct put a tiny drop of loc-tite on the lock rings to hold them in place, they will work loose if you omit this part.

here is the finished product I mark my hop up to use as refference and to see if it ever moves.

 

Thats it reassemble the gun and have fun

 

Doom

[boris the pict]

cheers for the replies guys, i'll give them a go tomorrow after I've finished marking.

[Tom Andrews]

An excellent idea, epicdoom, with only one tiny flaw.................the MP5 hop up is nothing like the M4 hop up!

[epicdoom]

Aye This was only to get an idea of how it can be done you will need to adapt it to the MP5 I did my MP5 when I bought it a year ago I didnt want to rip my MP5 apart for pictures

Guess I'll be ripping the MP5 apart tomorrow to show how I did that one. will post pic's and write up.

Joe

[Grifter_rn]

Hi guys,

 

I've done a couple of searches but came up blank so i'll ask you guys.

 

Every time i set the hop on my mp5 the first bb down the pipe pushes the whole thing back to 'neutral' what can i / should i do?

 

cheers

 

Boris.

 

this is a common problem for mp5 espicially the ones from china what i did was get a some heat srink tubes and put them on the hop lever keep doing this till it is tight enough with the foregrip on. now when you set your hop it will hold due the the the srink tubes. have done this to all my mp5 and they work lke a charm even on high fps they dont reset the one i that i play with a lot shoots at around 420 on .2 and the hope never resets hope this will help

[epicdoom]

Ok here it is on the MP5 Hop Up

Dissasembled and parts layed out

Ok to be clear this O-Ring is optional you don't need this one all the time. It largly depends on how the parts were molded. Anyhow if it is needed you will have to sand or file it down and Glue it in place with super glue.

its always a good idea to use loc-tite on this lock ring

your next O-Ring goes on the post that the arm attaches to

Arm reattached and screw installed, use loc-tite here also. Run the screw in till it touches the arm, check to see if the arm is touching the o-ring, if it is your gold, if not tighten it till it touches. If this causes the arm to sit funny on the cam gear you will need to use 2 o-rings on the post instead of 1.

This is what it looks like when your done. notice I only needed 1 o-ring. Sometimes you can just put an o-ring or 2 in this location and you wont need one at the cam at all. this is trial and error as stated, depending on how the parts were molded.

 

Hope this helps

 

Doom

[stealth monkey]

I've had this problem with my mp5. I just put a couple layers of electrical tape underneath the hop up adjustment lever to give added friction, worked like a charm. Either that or a bit of sticky-tac on the lever does the job pretty well. These are just easy quick fixes but some of the others look exceptionally good.