SLR semi auto problem WILL PAY$$$ for fix

Hey so I’m having so much trouble with the semi auto/single shot on my SLR gearbox it will not shoot one shot and will always just either be full auto poopy bursts or sticky and unresponsive

this is my third SLR Gearbox in the last couple of weeks that has done this and I’ve tried everything my brain can think of, I’ve searched and watched multiple ■■■■■■■ videos addressing the problem with no fix for me

I’ve just taken my third new SLR gearbox out of the box and given it a good test all standard no upgrades and single shot is fine works for days no problem, so I open it up being VERY VERY mf careful to not touch a damn thing that doesn’t need to be touched, changed cylinder head and nozzle, tappet plate, O-Ring, and 1.3 Spring I even managed to hold the anti reverse latch and trigger in place while opening the gearbox so nothing was bothered or moved

Put everything back together and gave it a test and it worked on semi auto single shot for about 1 mag and then started shitting the bed with a cheeky double burst then a triple then just went full auto on semi,

I’ve been severely disheartened and don’t know what else to do or where else to turn

Mosfets are too expensive unless there’s a $20 one that can fix this problem

All techs are prob busy because of Xmas and probably cheaper to just buy a new gearbox for $80

Anyway sorry for the long ass post I just really need some help with this I love semi shot it’s all I basically want to use ever, full auto is too loud and abnoxious so to be stuck with an ONLY full auto blaster I don’t even want to use it

Any help would be very appreciated and if anyone can give me a sure fire fix then money$ your way :)))

Wouldn’t a mosfet be cheaper than a new box? Not something I’ve looked into but even if they are expensive getting another $80 gear box hoping number 4 is the charm doesn’t sound like betting odds I’d take

You’re right but I also have 3 gearboxes I would like to fix this semi auto problem on and buying mosfets for all of them is not practicle

Yeah that’s a fair point

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Is the selector switch, on the inside of the receiver, slipping off of the selector plate on the outside of the gearbox?

Nope it’s all good and working as it should I can see the selector plate moving the cutoff lever and spring if I look down the side of my receiver, I’ve taken the safetey lock thing all the way out because that was kinda stopping the semi auto pushing the cutoff lever all the way down but it didn’t change anything with no safety it’s just full auto

Any cheap mosfets that will fix this? Seriously considering

Have you got the motor adjusted to the right height? If it’s too low or two high it can cause issues with semi auto etc…

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How exactly does it affect it? This might be what’s wrong with an old Wells build that I could never get the semi to work correctly.

adjusted the height very good multiple ways, had gears in with nothing else with grip attached to gearbox and got the height sounding good so i dont think thats it

Something I discovered with a jm9 m4 it was my first blaster and I played around with the motor height and when it wasn’t in the right spot it would cause the blaster to not always go through a complete cycle so then the next time it tried it to fire it was already halfway through a cycle and stuff up again…

Full auto worked fine, it was just on semi when you’re randomly pulling the trigger it would stuff up.

You need to have everything in there to really test it. Also make sure battery is powerful enough to turn motor, motor is strong enough to compress the spring, piston is moving freely etc etc.

If a lot of things are only just doing the job, when the motor height is not right it quadruples the problems and you get half a cycle etc etc


Spot on. Blasters in general are made to bare minimum specs to function. The moment you upgrade a part the stress transfers to another part. Welcome to the money pit. Arty Marty, Rattler, Hiroshima, and yes Calcifer, are very informative and will give you (mostly ) good advice. Spend some time here looking at previous post, full of a lot of bullshite granted, but you will find everything you need to transform your $200 200FPS blaster into a money sucking monster…ahem…wonderful masterpiece that kicks ass on any field and makes your competition call their hits


Does it do it on 7.4 and 11.1, I’m no electrical expert but maybe the contacts are rooted already.

I’m having the issue with my sons blaster where on semi the trigger gets stuck forward after it’s fired In semi mode.
After really close inspection I’ve come to the conclusion it may be the trigger spring being too weak.

The way semi auto works is the knob on the bottom of the sector gear hits the semi selector which then pushes the trigger contact up and over the trigger and back into the neutral position. When you let go of the trigger it should slide back under the trigger contact back to its home position.
So a stronger spring should help…I hope.
Otherwise I’m open to ideas guys🤙🏽

Perun V2 seem to be a good cheaper MOSFET to use to replace the trigger group, there is the ezfet which is cheap very small MOSFET very simple

Check your spacing on the contacts for the trigger. If they are too tight your semi won’t function because it won’t be able to break contact