Another Izzy malfunction question

[Bandgap]

Following @Oldnslow`s lead I thought to ask an Izzy malfunction question. I too own and MP-46M and it has developed a problem recently. The trigger mechanism has a noticeable two step release when cold. Sorry no photos. It all sound. It is only noticeable when you dry fire. Pull the trigger and hear a “click” sound this is followed by a “phut” sound. There is a noticeable lag between these two sounds. As you fire pellets the lag decreases until a single normal trigger release sound is heard. The normal sound returns after about 30 pellet shots. Velocity measurements are normal. Grouping is normal (i.e. not so good, my fault not the guns). The gun is about 12 years old and I bought it used just over a year ago. Has anyone run into this problem? Thanks in advance.

[Gwhite]

Sounds like something in the firing system is sticking due to dirt, corrosion, and/or lack of lubrication. Once it warms up, it stops sticking. I'd start by lubricating it. The head airgunsmith at Air Venturi recommended air tool oil, which is readily available at home stores (i.e. Lowes, Home Depot, etc.). Crossman Pellgun Oil should be avoided. Apparently it leaves a sticky residue (which might be your problem...).

[-TT-]

Goop on the sear. My AP-46M had a huge glob of it from the factory, same symptom. It's hard to get in there to get at the buildup, so you may have to resort to a solvent spray. But since it's recent, maybe just a drop of oil to soften it followed by a blast of compressed air to move things around.

[Bandgap]

Thanks for the comments. @Gwhite, I took your advice about air tool oil many months ago. When I oil the pump cup that`s what I use ... sparingly. The previous owner used Pellgun oil on the pump cup. He may have used it on the trigger workings as well. @TT, when/if it gets worse I`ll have a go with the compressed air and solvent.

[PeeWeeDaddy]

My $.02:
I know this procedure is not mentioned in the Owner’s Manual but, when storing my IZZY, I leave it with the pistol charged with air.
We do this for Crosman and Sheridan pump air rifles and it is recommended.
It keeps pressure on the seals.
Too, I keep the bolt unlatched
Lowered but not latched.

[Bandgap]

My $.02:
I know this procedure is not mentioned in the Owner’s Manual but, when storing my IZZY, I leave it with the pistol charged with air.
We do this for Crosman and Sheridan pump air rifles and it is recommended.
It keeps pressure on the seals.
Too, I keep the bolt unlatched
Lowered but not latched.

Interesting. I`ll try this and see if it effects the problem mentioned in the OP. I guess by design PCP`s are left charged all the time also. Thanks

[kevinweiho]

My $.02:
I know this procedure is not mentioned in the Owner’s Manual but, when storing my IZZY, I leave it with the pistol charged with air.
We do this for Crosman and Sheridan pump air rifles and it is recommended.
It keeps pressure on the seals.

WRONGO!

Single stroke pnuematic airguns should NEVER be stored compressed, their seals and valve mechanism were not designed to hold air for a long time, multipump pnuematics on the other hand, specially Crosman and Sheridan airguns, can be safely stored indefinately with a pump or two to close their valves against airborne dust and debris.

[PeeWeeDaddy]

Baloney

[kevinweiho]

Baloney

Please enlighten us where you got the idea that storing a compressed SSP will not damage the seals and valve mechanism.

[PeeWeeDaddy]

Because it works.
Trial and error.

[Vadym]

This is a known problem with older pistols and is caused by a weakened valve opening spring. If the pistop is loaded, the valve is opened by the action of air and spring at the same time. If a dry shot, then the valve opens only by the force of the spring, the force of which is not enough when the lubricant thickens in cold weather, and the valve opens with a delay or does not occur at all. Then one loud click turns into two weak ones, and then into one weak click. The problem is radically solved by replacing the valve spring, temporarily solved with liquid lubricant, or not solved at all, because it does not affect the quality of the hits.

[Bandgap]

Thank you for the explanation and solutions @Vadym.