Think I need a new motor

Well this is about my well's M4. When I got it it was shooting 350. I put in an upgraded spring guide bushing's shimed the gears and a 370 fps spring. The gun still shot but sounded differint... sounded over worked. I played with the adjustment for the motor lossened it up a bit and it sounded better but still over worked.

At the game I let a buddy shot my gun, he did a few shots were he ould tap the trigger as fast as he could so that it didn't shot bt the piston was back and then he'd tap the trigger again and it would finish the cycle. He did this a couple of times and then it didn't shot. I played with it a little at home. The piston was probably 3/4 of the way back. I took it apart and put it back together. It seems it can't pull the piston more then 3/4 of the way back unless I help it by pushing on the piston.

So as I said I think I need a new motor but am looking for some input before I spend money on it.

hmmm, I downloaded all the videos from mechbox.com 4 u and i'll put them on a disk. Mine after the rebuild sounded tight too me as well, but shooting next to the kids it seems ok. Very crisp and snappy but sounds, tight like you describe yours.

I did a lot of reading on this for you Bill, One important step in putting a gearbox back together is setting the timing. From other ppl having similar problems there was a host of suggestions, too many shims, or two gears rubbing together from not enough shims. I know it's been said that once the gearbox cycles the timing should reset itself, but the gun docs seem to be very adamant on setting the timing b4 it's put together or the piston will be out a couple of teeth and has to cycle further than normal to release the piston. One was fixed when they noticed the anti-reversal latch was dragging on their gears and had to sand it down a bit to get clearance.

https://www.youtube.com/watch?v=zm1jPdDsXc0

oh, was your battery wires getting hot? that would be a sign if you motor working hard.

It's not the timing. It was shooting but seemed like it was working hard. them it quit shooting. I'm farily certain it's not the shims.

well something dragging anyway...

What battery are you using Bill? Might want to check that, also try doing a 'loose' shimming job. It might be that once your gears are under pressure they are binding because they are too tight.

Are you running ball bearing bushings? Also what all do you have in there internally?

One workaround i read was to remove the "last' tooth", by filing it off, some gearboxes require it but obviously yours does not.

exert from that guide I mentioned..... the part pertaining to you is in the last paragraph.

Section 4 : Compatibility Issues (Things to avoid)

Part I: Piston/Cylinderhead matching.
1. Do not mix Boreup/Standard parts. This includes Pistonheads, Cylinders, Cylinderheads, and Air Nozzles. "NB" denotes 'Non Boreup' parts. "BU" sometimes denotes 'Bore Up' parts - sometimes parts won't be marked at all, and you just have to use deductive reasoning.
2. Do not use flat-faced Aluminum Pistonheads with flat-faced Cylinderheads. Doing so sends excess energy straight into the weakest point in your gearbox case - the front end. You have been warned.
3. Do not use flat-faced Pistonheads with 'funneled/tapered' Cylinderheads. Most Silent-type cylinderheads are funneled/tapered. Use a Silent-type pistonhead with funneled/tapered Cylinderheads. The Silent-type Pistonheads are designed to take all the force of slamming into the Cylinderhead on the edges, or rim, of the Pistonhead. A flat-faced pistonhead will eventually get it's rim/edge broken, cracked, or snapped off.
4. Do not use a domed/Silent-type Pistonhead with a flat-faced Cylinderhead. This is a no brainer. Besides having the Pistonhead trying to bend the Cylinderhead, the extra length of the pistonhead may push the Piston and Sector Gear teeth out of alignment in the pre-engagement state. Bad, bad, bad.

Part II: CA Yellow Pistons
1. The second tooth (from the 'insert spring' end) does not quite mesh correctly with the Sector Gear. Simply file off the entire thing to avoid excess stress or deforming to the piston.
2. The last tooth (metal) is out-of-spec. It's too big, and stresses the Sector Gear teeth. Either file the metal tooth smaller or replace it with any other brand's metal tooth.
Do those mods, and you should have a good piston. Many people use theirs stock with no problems,
but it's a game of chance if you do.

It's a well gear box in the well M4 i bought from Huang on ASC. I replaced the spring guide, shimmed the gears not loose, replaced the plastic bushings with metal ones then swapped what is supposed to be a 350fps spring for a 370fps spring.

Battery?

Check the shimming quickly, it probably isn't that, but its worth checking.

I wouldn't try to modify a piston to fit, too many potential issues with that. I think you are better off getting a new piston (brand name) and it should solve your problems. I'm a big fan of Prometheus internals, they're great and always well made.

You're motor should be fine, it sounds like your motor adjustment may be off. Do you have any after markets parts (i.e. motor, pistol grip?) The gearbox itself may even change the angle of the motor just that little bit that is required to strain your motor.

Check your batteries, make sure there is enough juice, swap back to the lower fps spring, change the piston and try again. If you work backwards and then add an upgrade element one at a time you should find the problematic part.

wonder if the bushings are too tight? do your gears spin freely without the piston in the mechbox?

Ya the gears spin freely. after reading that link you put in the manual section I'm going to go back in when I get some time and go through it.

Here's a link to what we discussed on the phone about piston teeth, another good read from the guide.

http://www.airsoftretreat.com/forums/index.php?PHPSESSID=00c9acf30f8d66188b85cac7a99bab8a&topic=77728.0


and here's an interesting article that might be what's happening?

http://forums.airsoftmechanics.com/index.php?topic=956.msg6627#msg6627

Checked a couple of things. the Angle of engagment is fine. The second tooth dose hit. Gear ratio is 18.1 unknown motor, cheap chinese one though so I think the motor is strugling to pull back the 370 fps spring.

Right now I'm thinking of turning this into a high speed gear box and getting that systema drop in one for a higher fps.

sweet!

Ya I had to take the second tooth off. Through in the 300 fps spring I have and it's shooting fine. so I'm either going to take the unported celinder and torque gears out of the AK and through them in with the 370 fps spring or take that piston that's too long and short stroke it and do a couple of other things to get rof up and use that as my cqb gun and get a drop in gear box with a high toque motor. I'm leaning to the latter.

hoo hoo! Can't wait to see it running!!

Ya I short stroked the piston, rate of fire is up quite a bit now. Going to save up a bit and get a drop in gear box and a good torque motor.

for the difference in $$ should you not go for the systema?

Got the Systema magnum motor just need the drop in gear box.

sweet!