P90 Question

[Iceman]

Just picked up a used TM P90 from Riddick (thanks!!) and everything is working fine except one thing. I'm not sure if this is normal so this is where I need your help. The range is only 50 feet but RoF is about right and that 50 feet is also on an arch (its full distance until it hits the ground). I was anticipating about 75 feet before dropping so is this about right for this gun? If not, will upgrading the spring and bushings be enough? I've read that the internals can handle about an M100-M110 spring without upgrading anything further, is this what you've seen as well?

Thanks for helping a new guy out!

[Beran]

The range should be much longer than that, at least 150 feet even from a stock TM gun. Are you sure you are correctly judging the distance? Also try turning the hopup all the way off and see what happens.

If disabling the hopup doesn't help, get someone to chrono it and see if it is shooting with a low FPS. If that is the case, there are many things that can be done to fix it.

[Iceman]

Measured with a measuring tape I have for long jump and triple jump on another test - 65 feet. The FPS seemed a little low so calculating time with a stopwatch and the 65 feet average and it taking about .7 seconds - I'd guess it to be ~93 fps - way too low! I'm using a fully charged 8.4v battery that I know to work well already so it's not that. Hop up is turned all the way up, and there is about a 15 foot shorter difference with lowest hop up setting. Further suggestions?

[Deleteplz]

Hop up bucking isn't working or there's a compression issue. My best bet. P90 mechboxes are super easy to work on, shouldn't be hard to fix at all.

[Iceman]

Being new an all I'm not sure how to do this - can you direct me to a thread or information about how to take care of that, diagnose if that is the issue, and how much it'll be to fix? Thanks again.

[Orwell]

This is a great thread with a lot of good information. Otherwise, I'd use this and this. Good luck out there, Iceman!

[Beran]

The bucking is an easy fix, but if the gearbox itself needs to be opened I would have someone else do it unless you are feeling adventurous. I don't know anyone that has taken apart a gearbox and put it back together and had everything work right on their first try.

For the bucking, you separate the upper and lower receivers on the P90 and then rotate the barrel/hopup assembly about a quarter turn and slide it out the back. From there you can probably figure it out, the bucking is the little rubber sleeve that goes around the barrel on the gun side of it. I'd take it off and put it back on, unless its torn or warped in which case I would replace it. Make sure you don't lose the nub, its a tiny little piece of rubber or plastic that goes inside the hopup and is notoriously easy to lose when you get down to the bucking.

[Iceman]

Thanks guys for all the help so far. I took it apart and looked around and didn't see a bucking at all. After viewing a youtube video for what I should be looking for, I in fact don't have a bucking so I guess that's the first place to go! Once this is fixed, if I continue to have issues with fps, what should I look to?

[Beran]

If there is no bucking, that is your problem. There is no seal to the front of the gearbox, so a large amount of pressure that should be propelling the BB is leaking out the sides. $8 worth of bucking later, you should be good to go. Make sure there is a nub too, it's very likely that's missing as well.

If I may ask, how much did you pay for the gun?

[Iceman]

Great, thanks! The nub is still there so it looks like I just need the bucking as you said. Does AONW or Airsoft Area's Shop have them for a good price or should I visit the online shops? $100 for the gun, no battery but I already had it, and a red dot.

[Riddick]

Come see me at summer slaughter. I'll give u a bucking there

Or take one at the shop. I'll call the guys to let them know

[Iceman]

Thanks Riddick! Cant make it to the Slaughter - too many family plans but I could stop in to the shop Wednesday probably. That work?

[Riddick]

I will be back on the 19th. So anytime after then will work

[Iceman]

Right, duh! We talked about that. Ok, may be that Friday then.

[Iceman]

Got it all fixed up. Was the bucking as it now shoots 350 FPS! Woot!