Morini CM162EI: Everything's leaking!

[_nc513_]

Hi,

I'm the owner of a Morini CM162EI (also known as CM162EA) manufactured in approximately 1998/1999. It's the old model with the 15 Volt photo battery.

I have two cylinders that very well may be just as old as the gun itself. One of them is leaking from the manometer end and the other from the end that attaches to the gun. Degraded seals, maybe? Is this a DIY job? Or would you just scrap these cylinders, due to their age?

Anyway, let's move on to the REAL problem.

I also have a cylinder that still can be used in competitions and will expire in 2029. It seems to hold pressure just fine, at least while NOT attached to the gun.

I today tried to shoot this gun after a maybe 4 year break (it was stored with the cylinder detached). I filled the freshest cylinder to about 160 bar and started to shoot. But, after about 10 shots, the cocking lever lock mechanism was engaged! A glance at the cylinder's manometer revealed that the pressure had indeed dropped from 160 bar to maybe 70 bar in just 10 shots. That's roughly 9 bar per shot. Terrible!

I refilled the cylinder to 160 bar once again and attached it to the gun tightly ... and the outcome was the same, except I might have gotten a few more shots out of it this time around.

I was wearing ear plugs, but if anything, I would say the gun might've sounded a bit less powerful than usual, i.e. it definitely did not sound like it was "on steroids". (Unfortunately I don't have any chrono measurements, at least not yet).

Shot placement seemed logical enough.

Any ideas as to what's going on here and how to fix it?

Thanks!

[Gwhite]

If it's leaking that fast, you should be able hear it. I'd ditch the ear plugs and see if you can tell where it's leaking. Also, if it holds pressure when you DON'T fire it, then the regulator is OK, and the firing seal can't be too bad. Drape a tissue over the top when you fire it. If it goes flying, your breech seal is toast. There are a limited number of places it can leak:

1) Cylinder to pistol seal (unlikely). If you can fill the cylinder OK, the seal in the cylinder is fine. Put a little grease (SuperLube) on the pin, and examine it for damage. If you transport the pistol with the cylinder completely loose on the pin, the threads in the back of the cylinder can chew up the brass pin right where it seals.

2) Regulator: Typically has several O-rings that can leak with age. If the regulator valve doesn't close properly, it will apply full cylinder pressure to the downstream seals, which can then let go.

3) Firing valve: If this doesn't seal, you should hear air coming out the muzzle with the breech closed. If this is sticking, it could open and close slowly, chewing up a lot of air.

4) Breech seal: This can only be an issue when you fire, so it's unlikely to drain your cylinder quickly unless something else is wrong as well.

It's old enough that a complete overhaul is probably a good idea.

[rmca]

I have two cylinders that very well may be just as old as the gun itself. One of them is leaking from the manometer end and the other from the end that attaches to the gun. Degraded seals, maybe?

Yes.

Is this a DIY job?

Hell no.
You will probably damage the cylinder trying to open them.
They have fine treads that are loctited and are very difficult to undo. The metal is soft and mars easily too.
And they are past their expiration date anyway (10 years!).

Or would you just scrap these cylinders, due to their age?

Yes. Do not repair cylinders, replace them.
The seals on a cylinder fail before the metal does. So, view it as a safety feature
Read this post to find out what happens when a cylinder fails (caution, strong images!). It will make my point clear.
https://targettalk.org/viewtopic.php?p=327930#p327930

I also have a cylinder that still can be used in competitions and will expire in 2029. It seems to hold pressure just fine, at least while NOT attached to the gun.

Your gun probably needs a new seal kit. This you can do.
I don't agree with Gwhite on the first point being unlikely. The gun to cylinder seal would be my first check.
From my experience it's the first seal to go due to the screw/unscrew of the cylinder.
The the points he mentioned are what I would check too.

Hope this helps

[_nc513_]

Thanks!

I once again filled the cylinder to 160 bar and then left it alone for some 20 hours. No air had leaked, as far as I could tell.

Then I installed the cylinder on the pistol. Now I could clearly hear a hissing sound, seemingly coming from where the cylinder attaches to the gun. I waited for about 9 minutes and then noticed that the pressure had dropped from 160 bar to about 120 bar.

In other words, the amount of lost air actually seems to depend on how long the cylinder has been installed on the gun. The number of shots fired appears to be quite irrelevant in comparison.

When one fill gave me only 8 shots, I was probably shooting a lot slower than when another fill gave me about 15 shots.

I suppose this latest evidence might be pointing mainly to issue 2), or what would you say?

[_nc513_]

I don't agree with Gwhite on the first point being unlikely. The gun to cylinder seal would be my first check. From my experience it's the first seal to go due to the screw/unscrew of the cylinder.

On the Morini, that seal is actually in the cylinder, if I've understood correctly? I'd say it "shouldn't" be particularly worn out, since the cylinder in question is new enough to have been installed on a gun max. 10 times or so.

[rmca]

On the Morini, that seal is actually in the cylinder, if I've understood correctly? I'd say it "shouldn't" be particularly worn out, since the cylinder in question is new enough to have been installed on a gun max. 10 times or so.

Check for damage anyway. It's not that hard to screw that o-ring so it doesn't seal anymore.
Then try to pinpoint where does the air escapes from. A paper tissue or soapy water help in this.

The three spots to check are:
1 - the muzzle - means the valve needs replacing
2 - the cylinder to gun - that o-ring needs replacing
3 - pressure reducer (where the cylinder screws in) to frame of the pistol - that o-ring needs replacing

There may be a little air escaping from the bolt, but the problem is in the valve if that happens.

[Gwhite]

The Morini cylinders do not use an O-ring to seal. It's a "U" seal. On a new cylinder, they should not leak, and if the cylinder doesn't leak when you fill it, the cylinder seal is fine. HOWEVER, they seal against the brass pin the cylinder screws onto. If that is nicked or damaged, the cylinder won't seal.

Benelli Kites use the same system, and are almost interchangeable. Here's what the pin on one pistol looked like after the cylinder was unscrewed, but left loose over the pin in the case:

Cyl Pin Scratches (sm).jpg (51.16 KiB) Viewed 722 times

The threads on the cylinders are sharp, and anodized (hard). If the cylinder bounces around during transport, they chew up the sealing surface on the brass cylinder mount. This one actually still seals OK, but I have no idea why, given it's condition...

[_nc513_]

Ok, I let someone who was recommended to me work on the gun. The results were not great.

They replaced a bunch of parts (see the pics below) and the leak appears to be gone, BUT ...

1. The loading lever is now angled wrong (I noticed this immediately while unboxing the pistol).
2. All parts of the loading lever mechanism now appear to be swimming in grease and I think (not 100% sure) it's spreading into the "pellet pit" and the barrel.
3. The pistol now sounds a bit tired and the MegaLink claims it's shooting only about 130-135 m/s, even though they said they adjusted the velocity to 154 m/s.
4. The loading lever does not safely stay put in the dry firing position (fully open). Correct me if I'm wrong, but I believe pulling the trigger of a CM162EI should NOT cause a fully open loading lever to move at all.
5. Firing 70 shots reduced the tank pressure by only approx. 40 bar.
6. After 78 shots, the loading lever became extremely loose and I decided the wise thing to do was to quit trying to use the gun.

I'd be happy to hear your comments on all 6 points above.

Also, was that a logical selection of parts to replace?

I suspect the washer that sits right under the loading lever's screw needs to be heavily curved, or else the loading lever will easily slip out of the dry firing position when you pull the trigger. Is this correct?

I don't dare to work on the loading lever myself, after reading the following comment by a very (yes, actually!) reputable gunsmith: "Don't do it! The threads in the frame of the gun are short and you never know what sort of glue they have used. If you use excessive force to unscrew that screw, the threads in the frame might just follow along with it! Rebuilding the threads is more or less impossible".

Should the inside of the barrel ever be oiled/greased?

[David M]

It sounds like the loading lever has been shimmed wrong or they have pinched the shim washers.

The loading lever bolt is a stepped bolt that tightens a sholder to the frame.
Under the lever are some brass shims that fit over the bolt shoulder and on top is brevell spring washer (curved to face the lever)
that gives tension to the lever.
Yours may not be aligned properly on the shims or wrong/missing shims.Make sure the shims are not caught under the shoulder.

I lubricate the loading lever pin, slot and frame slot only with moly anti fretting grease (wear points).

DO NOT fire the trigger with the lever fully open, it will release the sear and the hammer spring will thump the loading block.

Low velocity and low air use go hand in hand.
Try re-setting the velocity between 148-152 m/s. Screw the velocity screw in 1/2 a turn at a time,

[_nc513_]

Thank you, David!

It is certainly a possibility, that when they tightened the screw, the screw started to force the bottom shim down into the threaded hole in the frame. Does this pic give any further clues?

[kevinweiho]

The screw is misaligned and does not look properly seated, that's the reason it still wobbles. Whoever did this fix is definately not an "airgun smith", but a "franken smith" that doesn't know what he's doing...

[_nc513_]

It sounds like the loading lever has been shimmed wrong or they have pinched the shim washers.
Make sure the shims are not caught under the shoulder.

Well, I decided to carefully try opening the loading lever screw. Turns out it was relatively tight, but not at all super tight. It came out all the way smoothly and easily, as I suppose it should.

I believe you were 100% on the right track. It definitely looks like the bottom brass shim got caught under the shoulder of the loading lever screw.

The (removable!) part that the rod #162028 slides against appears to be in quite terrible condition, by the way. The previous tinkerer apparently decided to ignore this.

DO NOT fire the trigger with the lever fully open, it will release the sear and the hammer spring will thump the loading block.

This is interesting! The World Cup participant in this screenshot looks to be pumping the trigger, even though she has the pistol loaded and cocked (but cocking lever fully open). I also tried this myself, and I didn't feel any movement at all in the cocking lever. And when I listen, I don't hear anything else happening, except the solenoid clicking, just like when you dry fire with the cocking lever closed and the pistol not being cocked.

During the years 2006-2023, my CM162EI cocking lever actually was so "stiff" that it stayed very firmly in the fully open position, despite me pumping the trigger. But maybe that is not how it was designed to be?