[Shipwreck!]

My 98 is having problems.

Its a very old model maybe even 10 years old now, I'm not sure, it came to me used. It's modded with a Tacamo mag feed conversion kit. When I first got that the 98's sear assembly was an older version that wasn't even supported by the kit, so I had to get a new sear that would work with it. So the sear is brand new but still seems to have some trouble engaging the hammer. Every once in a while you'll get a two or three round burst out of it when the sear fails to engage through a couple of cycles. Also it's jamming fairly frequently. Couldn't say why, it's not chopping balls with the bolt so that's not it. I think maybe it's not getting enough pressure in the blowback to return the bolt. Also when it is firing the shots are dropping off bad, I don't have a chrono but it looks like it's shooting way too slow.

If anyone has any ideas what might be wrong with it, I'd appreciate some input, thanks!

[thrasher_565]

well i would try chrono it first could be too low pressure and take it apart and take a pic of the trigger and sear then we can look at it. oh and if that's the stock barrel a 12 or 14 inch barrel would help abit. weird to say the 12 inch gos farther.

This post has been edited by thrasher_565: 03 December 2011 - 08:17 PM

[Krazy8]

Without a chrono there is no way to determine your trouble.

Low pressure can create a pile of odd performance issues in the m98. Unless modified properly to run lower pressure, they really do need a high input pressure to work right.

Barrel length will not effect distance...velocity does that for you. Velocity in the m98 is effected by air flow from the valve to the bolt. Shorter barrels need more airflow to push the ball...if you are not getting that airflow you are not getting proper velocity and range.

One thing to look at...was the hammer changed out with the sear? They might not fit together very well if the hammer was worn down to match the old sear. The alignment could be just a touch off and not creating a good catch.

The valve could be getting old and not performing its job well creating a loss of air distribution and/or consistancy.

It could be as simple as the oring on the hammer quite truthfully....or not enough oil.

Get your hands on a chrono. Then start with the easiest solution and work from there. Be sure to test after every change so you know what made the difference in performance.

This post has been edited by Krazy8: 04 December 2011 - 02:34 PM

[Shipwreck!]

thrasher_565, on 03 December 2011 - 07:15 PM, said:

well i would try chrono it first could be too low pressure and take it apart and take a pic of the trigger and sear then we can look at it. oh and if that's the stock barrel a 12 or 14 inch barrel would help abit. weird to say the 12 inch gos farther.

Yeah, I do need to chrono it... I think the local shop does it for free, if so I'll get on that next weekend. And next time I crack it open I'll throw up some pics of the internals. Not tonight, all my tools are at the bottom of my go bag.

I'm not suprised the 12 inch is more air efficient. I mean even with your velocity adjustment maxed there's not going to be enough air going through to keep accelerating the ball down a REALLY long barrel like 14-20" those things are just for show/people who don't know how paintball guns work.

Krazy8, on 04 December 2011 - 01:30 PM, said:

Without a chrono there is no way to determine your trouble.

Low pressure can create a pile of odd performance issues in the m98. Unless modified properly to run lower pressure, they really do need a high input pressure to work right.

Barrel length will not effect distance...velocity does that for you. Velocity in the m98 is effected by air flow from the valve to the bolt. Shorter barrels need more airflow to push the ball...if you are not getting that airflow you are not getting proper velocity and range.

Blurg. I'm sure it's a pressure issue. Just don't know why the pressure's low. I maxed the velocity and no difference. Barel length can effect velocity but not as much as the actual velocity adjustment haha! With a given velocity setting if you change the barel length the velocity will be effected. That's why my A5 used to drop balls like tween when I would switch from my Flatline to stubnose in game. But yeah, Thrasher, the primary factor effecting range is your velocity, which is mostly handled by your velocity adjustment. As far as good barel length that's just about finding an air efficiency sweet spot, not sooo long that you need to crank the velocity to overcome friction, but not so short that you need to crank the velocity to reach 280fps before you run out of barel.

Quote

One thing to look at...was the hammer changed out with the sear? They might not fit together very well if the hammer was worn down to match the old sear. The alignment could be just a touch off and not creating a good catch.

Negatory, it's not gonna be either 'cause I don't have moolah for parts right now. That's a good call, in fact I'm sure that is the problem. How long do you think the sear will take to wear down to fit the hammer? 'Cuase in the meantime I don't think I really mind the occassional 2-3 round burst as long as it's shooting good. I'm mostly concerned with the pressure problem...

Quote

The valve could be getting old and not performing its job well creating a loss of air distribution and/or consistancy.

I'm sure the valve is crap, it's like a decade old. And like 4 years of that it spent rusting in a crappy shed before I took custody of it. No money for a new valve though. Blurgh.

Quote

It could be as simple as the oring on the hammer quite truthfully....or not enough oil.

Get your hands on a chrono. Then start with the easiest solution and work from there. Be sure to test after every change so you know what made the difference in performance.

Oof! That would be nice if it was just the O-ring. What does that O-ring even do? It just f-ing sits back there behind the hammer, it's not even around anything. I guess just a shock absorber so the hammer doesn't hit the end cap? It's not the oil, I oiled the sh*t out of it when I transfered the internals. But I'll get it chrono'd and see what I can do from there.

THANKS GUYS!

[thrasher_565]

most barrels had a set bor of 8" then it tapers out. the point of a longer barrel would be 1 to push against a bunker and 2 ( more space to put holes ) but not all longer barrels have more hols. Longer barrel = more friction and need more air with an exception of the "furious" barrel and "Iswitch" and "python". also the bor sise can efect the distance and we no this because the .50 cal dost go as far as the .6xx cal so you need to way the weight to the psi the get the maximum distance. Rifling will not do a thing unless its done proper.

[JaguarShark]

thrasher_565, on 04 December 2011 - 10:28 PM, said:

Rifling will not do a thing.

Fixed.

[Puzuma]

Are you using CO₂ or HPA? Does the tank you are using preform properly on another marker? Is an expansion chamber/regulator being used and working right?

[Shipwreck!]

Puzuma, on 05 December 2011 - 10:25 AM, said:

Are you using CO₂ or HPA? Does the tank you are using preform properly on another marker? Is an expansion chamber/regulator being used and working right?

I'm running CO2. Yeah, I've got a lot of tanks and the all work fine on my A5. Nope, no expansion chambers or regulators on anything...

[cdrinkh20]

I think Krazy8 meant the o-ring on the hammer itself...if it's worn then the hammer won't be moving fast enough to strike the valve with the force to let out enough CO2 to blast it back/it won't come back fast enough to catch the sear (due to friction/lack of seal).

Have to agree, probably the hammer not catching well.

It could ALSO be just your main spring - when is the last time you put one in? If it doesn't have enough strength to push the hammer forward it's not going to release enough CO2, etc.

Reminds me of the 98c I sold a friend... I used it 2 years solid (used) and started playing paintball with HPA - he bought it from me, put in CO2 and it refused to work properly at all...either super high or super low velocity, jams, etc. My FPS used to range +/- 5, his was between 340 and 220 fps. Never figured out why, next time I saw him he had bought a Phenom

[Krazy8]

Thrasher...your sentence structure makes it seriously hard to accept you answers. And if you think bore to ball ratio is the reason .50 is less effective than .68...you should not be posting here with barrel info. In fact...the barrel has nothing to do with why his m98 is dropping output pressure.

Now then.

Yes that floating o ring behind the hammer is simply a shock absorber so the hammer does not bash into the spring guide and bend it. Keep it there.
The oring I was thinking about would be the one on the Hammer. If it is bad you can lose blow back air around the hammer and it will creat sear catch troubles.
In fact. polished internals can do that as well if done too aggresivly.
Lack of oil on that oring can also create to much drag causing the sear to miss...that is why I thought of it.

But...I had an A5 doing exactly what you are describing and a new valve fixed...Capt. Obvious is still using that gun today. And it works great.

Years ago...prior to the Custom 98 there was a valve rebuild kit for the M98. I used a kit on my 98 and it made a difference in performance. My M98 serial number is 16544, yes pretty old.
If your gun is pre "Custom" then you might be able to use one of these kits to rebuild the valve, or fake it and buy the individual parts to make your own kit. Last I looked they were hard to find, but I see all the parts on ebay...could be done for under $20.
If your gun is Post "Custom" then you can simply buy a whole new valve for a bit more and simpy drop it in. Just looked...$24 shipped on ebay.

[Warpaint]

Go to the Tippmann website and try their troubleshooting tips under tech support...try the simple, cheap fixes first, and the more complicated, more expensive last...but, you'll probably end up replacing the power tube. The factory installed power tube is plastic and these crack often, especially from the cold, dropping the marker or similar impact damage...upgrades are available for another $10-$20 bucks that are made from metal. When power tubes crack or seals wear out pressure won't stay up.

[Krazy8]

Oh....good call on the power tube. I have seen quite a few of those fail in the years....I always replaced mine with aluminum prior to failure so it did not accure to me!
JCS offers the best aftermarket powertubes. And I have found them on Amazon and ebay for far less cost then retail.

This post has been edited by Krazy8: 11 December 2011 - 12:53 PM

[Shipwreck!]

cdrinkh20, on 05 December 2011 - 07:48 PM, said:

I think Krazy8 meant the o-ring on the hammer itself...if it's worn then the hammer won't be moving fast enough to strike the valve with the force to let out enough CO2 to blast it back/it won't come back fast enough to catch the sear (due to friction/lack of seal).

Have to agree, probably the hammer not catching well.

It could ALSO be just your main spring - when is the last time you put one in? If it doesn't have enough strength to push the hammer forward it's not going to release enough CO2, etc.

Reminds me of the 98c I sold a friend... I used it 2 years solid (used) and started playing paintball with HPA - he bought it from me, put in CO2 and it refused to work properly at all...either super high or super low velocity, jams, etc. My FPS used to range +/- 5, his was between 340 and 220 fps. Never figured out why, next time I saw him he had bought a Phenom

Good sugestions! I'll check all that out next time I crack it, probably at least a week because I've got a lot of stuff on my plate right now...

Hopefully it's just the O-ring or main spring, that would be perfect easy fix!

Krazy8, on 05 December 2011 - 08:04 PM, said:

Thrasher...your sentence structure makes it seriously hard to accept you answers. And if you think bore to ball ratio is the reason .50 is less effective than .68...you should not be posting here with barrel info. In fact...the barrel has nothing to do with why his m98 is dropping output pressure.

Now then.

Yes that floating o ring behind the hammer is simply a shock absorber so the hammer does not bash into the spring guide and bend it. Keep it there.
The oring I was thinking about would be the one on the Hammer. If it is bad you can lose blow back air around the hammer and it will creat sear catch troubles.
In fact. polished internals can do that as well if done too aggresivly.
Lack of oil on that oring can also create to much drag causing the sear to miss...that is why I thought of it.

But...I had an A5 doing exactly what you are describing and a new valve fixed...Capt. Obvious is still using that gun today. And it works great.

Years ago...prior to the Custom 98 there was a valve rebuild kit for the M98. I used a kit on my 98 and it made a difference in performance. My M98 serial number is 16544, yes pretty old.
If your gun is pre "Custom" then you might be able to use one of these kits to rebuild the valve, or fake it and buy the individual parts to make your own kit. Last I looked they were hard to find, but I see all the parts on ebay...could be done for under $20.
If your gun is Post "Custom" then you can simply buy a whole new valve for a bit more and simpy drop it in. Just looked...$24 shipped on ebay.

Huh, I lubed the crap out of it when I transfered the internals, so that shouldn't be it. Nah, mine isn't pre custom, unfortunately. I'm really hoping its a bad o-ring or main spring as suggested because I can't afford a new valve right now...

Warpaint, on 07 December 2011 - 07:21 AM, said:

Go to the Tippmann website and try their troubleshooting tips under tech support...try the simple, cheap fixes first, and the more complicated, more expensive last...but, you'll probably end up replacing the power tube. The factory installed power tube is plastic and these crack often, especially from the cold, dropping the marker or similar impact damage...upgrades are available for another $10-$20 bucks that are made from metal. When power tubes crack or seals wear out pressure won't stay up.

Thanks for the headsup on the tech support, actually didn't think to look there. I've never had one crack on me and my A5's going on... eight or something, years old that is, and God only knows how old the 98 is, but I just had it open a couple weeks ago and I didn't notice any cracking of the power tube, but I'll double check that next time I open it up...

Then again it seems to be blowing a lot of CO2 into the mag when it fires, froze up and deformed a lot of paintballs in the mag when it was shooting full on automatic before I got the replacement sear... maybe it is a failed power tube...

Krazy8, on 11 December 2011 - 11:52 AM, said:

Oh....good call on the power tube. I have seen quite a few of those fail in the years....I always replaced mine with aluminum prior to failure so it did not accure to me!
JCS offers the best aftermarket powertubes. And I have found them on Amazon and ebay for far less cost then retail.

Awesome guys, thanks!

I'll check it out as soon as I get a chance and update, maybe with pics...