echo 1 E90 mechbox problems

i have an echo 1 e90, but it is a much older model, about 4 years old. i purchased it off a guy for 30 bucks to try and fix the gun. i replaced the obvious problems, a worn out pinion gear, and a stripped gears. when i replaced pinion gear it did not go all the way down on the motor pinion and at least by my hands i could not get it on any farther. i had it shooting a day ago after completely re greasing the gears and piston, currently th problem im having is the piston on gets drawn back about an inch and a quarter at the most, and it just sits there like the battery is dead but its not it is almost fully charged. ive dissembled the mechbox about 10 times now and i cant see anything wrong with it, and i really dont want to take it to someone to get it fixed because i dont have much money to do that. has anyone else had this problem and fixed it?

Check your shimming, what kinda of battery? If you give up we at Airdog can get it going for you.

its a mini type 8.6v battery i tested it its actually putting out 9v at sometimes. and when you say shims your talking about the the copper disks between the bushings and the gears right, because they are there.

Just because there are shims there doesn't mean it is shimmed correctly. If you didn't shim the gear replaced that's probably your problem. Also just because the battery has 9.0 volts doesn't mean it is a good battery and is providing the amperage needed.

Rhino is a Master Gun tech so he knwos what hes talking about.

To reitterate what he is saying,

Your battery could be bad even if the voltage is good or higher. It's not the voltage it's the amperage that makes a battery good.

Your shimming could be too much, you may have too many shims between the gears and bushings causing the gears to be squeezed in really tight and have too much friction for the mini battery to spin them.

Try another battery of the same voltage that you know is good to eliminate the battery as the problem. If it works it's the battery, if it doesn't its probablly your shimming.

For shimming look up tutorials for shimming a version 6 gearbox on youtube, but my suggestion would be to take it to Airdog if your not skilled at shimming or scared to try it and re-try it and re-try it until it's right. Shimming is a very big part of the Gearbox working properly and is very tedious to get it right.

ok thanks ill check that out

with just the gears in place, close the gearbox and see if the gears spin freely. if you have a damaged gear, it will lock up or if the shimming is not correct, it will not make a complete cycle. also, you may have a damaged piston that doesn't mess well with the sector gear.

if all those check out fine, you may have a bad motor or bad battery.

if you get tired of trying to fix it, i'll buy it off you for what you paid. i can use spare p90 parts. my trigger housing started cracking around the bolts from constant removal and retightening. i also stripped a few gearbox threads (my bad).

rhino, i found a fix for the worn out cutoff lever. shave down the cutoff lever window and apply some heat to the cuttoff lever and give it a little bend (as you have done before). this puts the cutoff lever closer to the sector gear chip. works flawlessly and there's more meat on the lever to sector gear contact.

too much heat and the lever will melt. not enough heat and the lever will crack.

it was the battery. just got a new one and fires fine. but now it is unusually loud and every now and again it misfires one or two rounds. could this be the shims as well?

What is it that is loud?

If its a loud whining sound when the motor turns you need to adjust the motor hieght. Check for videos on youtube on how to do that. Better instruction than me trying to type it.

When it misfires does the motor just spin or does it not pull the spring back all the way, or is it just need firing a bb? Need a little more detail.

i shot it again today, both dry fire and with rounds in it. its not as loud when dry firing but when there are rounds in it is sounds like the piston head (which is aluminum) is hitting against something metal but i disassembled it and the air out nozzle still has its rubber pad on it. and the motor is very loud as well, ive seen many videos of people firring p90's and the first round is loud but after that it quiets down a bit mine doesn't quiet down. also once i put it back together it stopped misfiring but its still making the noise

HECK YES!!! i fixed it!! turns out the barrel wasn't seated all the way in to the hop up bucking. oh happy day.

mwilson wrote:HECK YES!!! i fixed it!! turns out the barrel wasn't seated all the way in to the hop up bucking. oh happy day.

Congratulations!