Marauder Lost Power(FPS) From Last Year

[USAFANG6799]

Marauder 22 caliber has been slowing losing power from last years chrono readings. It's lost about 40+- fps using same pellets (Crosman 14.3 hollow point) @ same 3000 fill PSI.
Where do I start looking? Want to eliminate the simple things first before I tear into it and make more problems than what I started with.

Many thanks!

[Motorhead]

Stock or modified ?
Factory hammer or MDS ?

[USAFANG6799]

Stock, no mods what so ever.
Took it apart about two weeks ago to look at condition of transfer port o'ring and inspected o'ring for probe.
All looked good.
No problems with holding/leaking of air with months on end of a fill.
It's probably going on three years old now. I doubt it has 500 pellets through it.

Thanks for the quick response from the Godfather of Marauders from what I understand 

[Motorhead]

Gunked up hammer ( Dirty or thick lube within bore where it slides ) is the most common problem.

[PeruvianHunter]

I think it's the hammer spring... replace it with a new one and try again

[USAFANG6799]

Gunked up hammer ( Dirty or thick lube within bore where it slides ) is the most common problem.

Ok then while I'm in there should I do any other PM(preventive maintenance)?

I think it's the hammer spring... replace it with a new one and try again

Ok many thanks guys!
Much appreciate the wisdom.

[Motorhead]

Hammer springs honestly don't just get weaker by sitting there ... If left cocked for a few months, perhaps

[mann]

The hammer spring adjusters for putting tension on the spring have a tendency to back out or loosen on the Marauder's which makes you loose fps

[tracker1955]

I don't think it would be a bad spring. Like Motorhead said gunk were hammer slides and or hammer spring adjuster that backed out.

[USAFANG6799]

Hammer springs honestly don't just get weaker by sitting there ... If left cocked for a few months, perhaps

As a golden rule I never leave any of my PCP's or springers cocked for an extended time. I also never push the bolt in the breech so that the oring is compressed.

The hammer spring adjusters for putting tension on the spring have a tendency to back out or loosen on the Marauder's which makes you loose fps

I don't think it would be a bad spring. Like Motorhead said gunk were hammer slides and or hammer spring adjuster that backed out.

I have on a couple of occasions turned the hammer spring until the fps went back up via my chronograph. Wasn't aware that Marauders had a tendency to back out or loosen. Maybe this is the problem? Any recommended fix for this?

[triggertreat]

It could very well be a dirty hammer as they do take up dust thru the hole in the end cap while shooting them.  If it is gummed up in there that would show up by possible velocity decrease by a small amount, but more so would show up as a higher extreme spread or more erratic velocity differences between shots.


The hammer spring adjustment can back out while shooting, but the stroke adjuster (HT) is more common, especially if it has been turned a few times already.  You can turn HT (small 1/8" adjustment) a 1/4 to a half turn counterclockwise to see if the velocity gets back to normal.

[tracker1955]

I put a twin spring system in mine, set it and forget it.

[Dairyboy]

Looks like these guys have it covered for you! I'd guess one of the adjustments could have moved as well over the years but doesn't hurt to take apart and clean the hammer area

[USAFANG6799]

Looks like these guys have it covered for you! I'd guess one of the adjustments could have moved as well over the years but doesn't hurt to take apart and clean the hammer area

I don't think it's ever been apart to that extent so it's quite possible the hammer needs a good cleaning.

Thanks for your input.

[Taso1000]

Are Marauder poppets susceptible to poppet seat flow if stored under high pressure for a long time like the Sumatra's are?

USAFANG67, when you were in the gun recently, did you get into the valve an possible see the acetal poppet?

Thanks,

Taso

[USAFANG6799]

Are Marauder poppets susceptible to poppet seat flow if stored under high pressure for a long time like the Sumatra's are?

USAFANG67, when you were in the gun recently, did you get into the valve an possible see the acetal poppet?

Thanks,

Taso

I've never hand it apart to that extent. The only inspection I've ever done was down to transfer port.
As a rule unless I have a reason to take something apart to that area I'll leave it alone. I don't want to compound the problems I already have.
Since the rifle was holding air for extended period of time I ruled that area out. That is unless I seek better advice/reasons like I'm doing now.

I like your inventory of air rifles 

[Taso1000]

I agree on trying the simple stuff  first and not opening new cans of worms.  Not that marauders are wormy, but I have broken stuff on investigation.   

I have read 2 instances where Sumatra rifles were stored with almost 3000 psi and the poppet material flowed into the throat of the valve and acted like an obstruction and a cork.

Thanks about me inventory.  I need to thin out the herd as my needs and wants have been fine tuned as I experienced more airguns.   

Taso