M98 burps in full auto with response trigger.

[COMMANDERBOND]

My custom M98 burps in full auto as part of automatic with response trigger. Its notconstant but sporatic.
It’s another custom marker. I was using a standard hopper vs an electrical hopper. This setup worked fine for several years. However I was previously squeezing off 3/4 round bursts at distances of up to 70-100’. I was happy to getting by with the lighter standard hopper

Yesterday’s games were in and out of steel containers ............. QCB.

I am assuming the marker is hungry for an e-hopper or perhaps the sear is worn. Maybe the response is choking off the air.

[BrickHaus]

We need more information to help sir.

Whats the air source today? Same as before?

im not sure if you are saying when you say burping.

when burping is the marker failing to re cock? Or is a burp really a response string you desire?


If the marker is failing to re cock, try burying your FVA back in. Im willing to bet todays paint is tiny for that 98cs barrel. So you likely backed the FVA almost all the way out to get to velocity. Im assuming a lot here.

If you feed me more info, Ill try to help.

[OpusX]

May need to sharpen the sear to catch better if it is missing. Myrkul has some experience tunning his 98RT

[COMMANDERBOND]

" Whats the air source today? Same as before?" it's possible i was using c02 back then - more boost.
" burping - like slipping..........almost like failling to recock or partial recock"
velocity is ok......270's
i have a similar marker with no issues. on semi auto there is no issues.
Its like it cant sustain automaticfire.

thanks

[Trbo323]

What barrel and length?

98s need some back pressure. If you are running a short barrel for cqb it could be that there's not enough back pressure.

Photos are the easiest way but what's the full setup?

An x chamber while not helping the air specifically can help keep air ready to go in front of the valve and can often help an RT

On a side note, does anyone even make expansion chambers anymore?

When was the last time you did maintenance on it? What was done? Oiled it recently?

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[snaparen]

If my 98 starts to sputter and I am not low on air pressure, the first thing I would look at is the o-ring on the hammer. Then check for excessive wear on the sear and where it catches the hammer

[Myrkul]

Could be a bunch of little things. Just freshened up my 98 R/T the other day actually.

If it's only burping at high ROF and not on standard semi auto, I'd be willing to bet your sear spring is starting to wear out. I think back in the day the R/T's came with stronger sear springs to help combat this, but the new kits might have dropped it, or it just might have never been installed.

Sear could also be worn out, or your valve might be out shooting your tank if the pressure is too low, might be an obstruction (ie crap) in the gas line choking air flow, hammer "O" Ring might be going bad, or your bore might be too big. R/T's can be SUPER picky.

[COMMANDERBOND]

l

[COMMANDERBOND]

like photo but with response setup. I have2 -this is the better one. The other one sputters with a long and a short 8'' barell

[COMMANDERBOND]

actual marker

[Myrkul]

I would very much like to see the internals on this. More pictures please.

[Trbo323]

Any internal modifications or is it all stock underneath?

When and what was the last maintenance you did?

Have you oiled it recently?

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[COMMANDERBOND]

Any internal modifications or is it all stock underneath? mostly a trigger linkage

When and what was the last maintenance you did? about 2 years ago

Have you oiled it recently? I usually spray silicon oil in asa and hammer area

[COMMANDERBOND]

There are no hicups on semi so i assume its the sear - at least i have a replacement. I dont have all the different o-rings

[Trbo323]

Hammer o ring could easily be your problem as well

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[Toestr]

I'd just give it a complete rebuild regardless and see if it persists. Sear spring is my bet for the issue. The links should all be tight together when you remove it (if it's the extension spring version). A good way to test this is to switch to a stronger mainspring. The cycling issues will get worse if it is the sear spring. The sear is probably fine. The only guns I've ever seen the sear go bad on are various ex rentals.

I'd also recommend you stop using silicone spray oils. Many have solvents that will eat urethane. For years the local field's idea of 'fixing' a gun was to spray half a can of WD40 into the breach and dry fire. It would work for a bit once it trickled down to the hammer. But since WD40 is a quick drying solvent that leaves a thin coat of oil (meant for rust prevention); not a true oil; the hammer seal would just dry out by the next game. It would also dissolve any paint, dirt, aluminum dust etc and deposit them in the lower tube and sear slot. All that stuff dried to a solid mass by the time I got to it.