Tokyo Marui M9 U.S no longer hopping. SOLVED: ONLY TWO YEARS LATER

[Asomodai]

Hello all. 

For the past three skirmishes, my TM M9 (Adjustable hop) No longer seems to want to create any hop. 

I thought the original rubber may have died, so I changed it to a Prommy Nineball. However this has done nothing to rectify the problem. I can see when I adjust the Hop wheel, the nub appears in the barrel where and when it should. 

However, despite the nub being present, I get no hop... Any ideas?

The rubber is dry, no silicon oil in any wrong places. 

Ta!

 

[Guest]

Is the hop actually staying on when you shoot?

 

[Asomodai]

Is the hop actually staying on when you shoot?

Are you saying it could be that the arm the holds the nub is not staying in place when firing? 

I couldn't say. 

 

[Guest]

I mean do you have to wind it back on again? It’s possible the arm is flexing, or even stress fractured, though unlikely

 

[Asomodai]

I mean do you have to wind it back on again? It’s possible the arm is flexing, or even stress fractured, though unlikely

No. The dial stays put regardless of how many times I shoot it. The nub stays in place in between shots at least. 

 

[Guest]

No. The dial stays put regardless of how many times I shoot it. The nub stays in place in between shots at least. 

if it were me, I’d take the hop arm out completely, and see what difference it makes

 

[Steveocee]

What gas are you using? It's been pretty cold lately, if using 144a or old/rubbish green then it may not be generating enough power to take advantage of the hop.

 

[Asomodai]

What gas are you using? It's been pretty cold lately, if using 144a or old/rubbish green then it may not be generating enough power to take advantage of the hop.

It's been happening for the past three months. I use Ultra-air. 

The power is there, 270 fps.

 

[Steveocee]

Worth trying to shim under the hop arm? I'm not 100% on the shape of them but can you cut anything to go under it to put more force onto the BB? If that doesn't work then it's almost certainly the arm is stressed and needing replacement.

 

[Guest]

I’ve had nothing but trouble with Ultra air, in consistent and weak. I only ever use Nuprol/WE green or red now

 

[Asomodai]

I finally fixed this! 

The hop arm was too sharp and it carved out a channel on the plastic wheel adjuster. 

I bought a replacement Maple Leaf wheel, but the channel is too wide to bring the arm down to hop enough. 

I purchased a new replacement stock TM M9 arm and two new wheels, lubed them up and installed. I am now hopping .28's easily. I may need to do some adjustment to the arm to get it firing completely straight, but otherwise all looks good! 

 

[emilianoksa]

Apart from your hop problem, how has your TM M9 held up over the last two years?

It is one of TM's most impressive looking guns IMO. Put it on display and it looks like the real steel. Are you still happy with its appearance or does it scratch easily?

 

[Asomodai]

Apart from your hop problem, how has your TM M9 held up over the last two years?

It is one of TM's most impressive looking guns IMO. Put it on display and it looks like the real steel. Are you still happy with its appearance or does it scratch easily?

Well I haven't used it in two years! It performed "ok" before the issues. My HiCappas are better. Using a polymer retention holster has given the plastic slide some rash so it definitely looks plastic. 

I used it at a skirmish on Sunday and seemed perfectly fine to me.