TM FN 5-7 advice required

[ScopeTacular]

Evening all,

I've got a TM 5-7 which doesn't seem to want to fire properly. Upon pulling the trigger with a fully gassed magazine, the gun will semi-cycle the slide. Thereafter, I have to rack the slide again and again I'll have the same result with semi-cycling of the slide. I've tried cycling the gun with different gasses in the hope that would point me in the right direction......it doesn't. I've got 3 new mags for it, which I've tried - these make no difference.

Unsure as to what the issue is exactly. However, I imagine it has something to do with the gubbins in the BBU.
Could anyone offer any help and/or advice to help resolve this issue?

Many thanks in advance folks!

[ElZer0]

Re: TM FN 5-7 advice required

Get a vid up

[ScopeTacular]

Re: TM FN 5-7 advice required

As soon as I'm home and can get my hands on it, I will do. For now, that's about as good as I can describe it at present.

[hapi]

Re: TM FN 5-7 advice required

Sounds like the piston and valve are stuck within the bbu, could be crap inside, piston seal worn or bbu springs U/S

[ScopeTacular]

Re: TM FN 5-7 advice required

Here's a short video highlighting the issue I'm having:-


http://youtu.be/2Gvh6XbNi_s

[Apurturesci]

Re: TM FN 5-7 advice required

Looks like the valve knocker isn't locking forward. Take the slide off and look into the grip/frame. Cock the hammer, press the sear/valve 'buttons' on top of the hammer unit to set it ready to shoot. When it shoots, does the silver valve knocker protrude into the magwell properly? It should lock forward.

[ScopeTacular]

Re: TM FN 5-7 advice required

http://youtu.be/QQ5a_uB1Hg4

[Apurturesci]

Re: TM FN 5-7 advice required

Interesting, it looks very much like the little sear that holds the valve knocker forward is missing. It should be in the hole next to the hammer, and clicks down when you push it. You said you bought it used, was this long ago? You should contact the seller about a refund, because between the snapped valve knocker and the missing sear there is no way it'll function. Take a look at this:

http://www.hyperdouraku.com/airgun/f.../partslist.gif

It looks like parts FN46 and 45 (spring) are missing - luckily it looks like you can get part FN46 cheaply in the UK.

[ScopeTacular]

Re: TM FN 5-7 advice required

I must have got it circa a year ago. Supposedly in "good, working condition"

Is there any chance of getting a replacement valve knocker or is it like hens teeth?
Thanks for the help thus far!