Hey guys,
So i have a TM M4 w/ some upgrades. My problem atm is that my motor starts getting hot. I have a Systema Magnum Motor (long) and a 120 spring. Why would it be getting hot? It only seems to do it when i run it on full auto for a bit. Typically i shoot it on semi, but it seems to over heat FasT w/ full auto.

Second question: I seem to be loosing compression somewhere, i just upgraded the hop up, so that's not the problem. I'm thinking I'm gonna need a new cylinder head, maybe a new piston head? and a tappet plate, but i'm unsure. It was shooting 200 feet w/ nice groupings no problem at all. and now she's barely shooting 170 and i'm having to rain them if they go that far :S. which is REALly bugging me. This just started happening, so i'm thinking something is wearing down getting loose etc. Info advise would be great!

*Edit* Thought about it some more today, and it is definantly shooting louder also, if that means anything.

thanks guys!

the compression may because of a bad oring and or piston head, i have heard people talk about upgrading the hop up and or barrel and had to upgrade their cylinder, as for the motor getting hot ,all i can say do is buy a vented motor plate, i have one and my motor gets still gets hot,hope this help

i remember you sayin somethin bout that when we were out that way...tha motor situation,u might have to get a ultra high torque(that might pull tha spring eazier),& az for tha compression,if u took tha gearbox apart yourself,i'de jus go bak in & make sure your o-ringz & all are in place & pushed into tha cylinder,az long az you know how to diss/reassemble...it cant hurt anything...

You are loosing air compression in your cylinder. There are two points that allow air to leak at the cylinder. the o-ring on the piston head and at te cylinder head. Yo ucan test the compression by putting your finger over the nozzle on the cylinder head and manually push the piston through the cylinder there should be fierce resistance. I fyou think it is the cylinder head, you can check it like a air leak on a tire with soapy water ti identify the leak around the seal.

You have a ton of torque for such a weak spring. You should isolate your endbell before you scratch the finish and allow it to arch. I used standard torque gears for 450FPS springs. Do you use a fuse? What kind and voltage battery do you use? You might want to check out airsoftmechanics they have essentially "fixed" the magnum motor. Using high speed gears or a 450FPS spring would help your motor. Its meant for M130 springs and up on standard ratio gears. Dropping your gear ratio will increase the torque load to a healthier level for that motor.

Check your motor height.
Get a mosfet for extreme-fire.com

You velocity is low due to bad compression. You could have a leak in a few places.
From cylinder to hop-up;
telfon tape you cylinder head and replace it back in your cylinder
inspect you piston head
replace your o-ring with a #14 from lowes or HD
inspect your cylinder head's nozzle for damage (the tube should be rigid and stationary)
replace your air nozzle with an o-ring air nozzle (I like deepfire)
inspect you hop-up bucking for damage (torn)
remove and apply a few drops of 100% silicone oil on your barrel and re-install your bucking (I use RC car shock oil, look a RC car hobby shops. If you have a gas pistol get 10w oil and use that with propane and general lube for maintenance)

First guess is your o-ring. Second guess is your air nozzle. I have broke a TM piston head before and I have seen several cylinder head break too. I'd only question that since your pushing such high rof.

Compression is not a big deal, tedious, but easy. The magnum could be a pain. Prepare yourself once you register at airsoftmechanics.

Wow thank you! I just got done putting my gun back together. Come to find out...after taking apart my hop up...the nub was never installed. I took it out of the package and put it in my gun hoping that would solve the problem. After it didn't i posted this thread. So, yes i got a nub and it's shooting much better.

After taking apart the gear box, Not only do I need a new o-ring and air nozzle like you guys said ,but i will also need a new piston head as well. The piston is fine as of right now, but in a few months I will most likely need a new one. After a nice clean, and lube the Rof went up slightly and my gun sounds much better.

But to answer your questions Admin, I am running it w/ a 4700 mAh battery. I don't have a fuse, although that's an excelent idea. I'm a bit unsure about the 450 fps spring idea, because i wouldn't be allowed to use it in most places would I? unless i was a DMR. But the high speed gears I will definantly purchasing in the near future.


Thanks again for your help everyone!

You really pounded the f#ck out of your system. Are you running bearings or bushings? Please OH! please say bushings. If you are not you are probably not rungging 8mm and thats just another thing to say thats going to break. The bad news is that when bearings break the micro sized steal BBs spray into your MB and just F#CK YOUR SH!T UP! If you're stuck at 7mm, you can try Kanzen 7mm ceramic bearings. They are top-of-line and have had a great service record of abuse. Safe side would be to go to 8mm and better yet 8mm + kanzen.

What voltage? 4700mah is great but 8.4v, 9.6v & + is a big difference. Using Deans yet? What about a mosfet? If your semi is no longer semi active braking will fix that. Check out extreme-fire.com

Admin

I'm surprised you're not over 25rps. You will be after the mosfet though. I gained 7rps off of mine in my high rof setup. Not saying you will too. You gain more the higher your base rof is without it. I was at 27rps prior to my SW-Computer.