Izh 46(M) breech block

[UnGe]

Does anybody know, what part/parts are responsible for keeping the breech block up after cocking?
Mine just does not want to stay up, requires raising after cocking. Started from not staying sometimes, gradually went to always dropping.

TYIA

[m1963]

Look at spring #4 in the attached diagram (directly below the words IZH 46M). It may have just come unhooked. (That has happened to us, in the past.) There are also some instructions for disassembly on Pilk's website.

http://www.pilkguns.com/izh46ex-htm/

[UnGe]

Thanks. #4 is in place, not worn off and well hooked, problem is probably with something else :(

[Gwhite]

It's been a while since I was inside one, but I think it stays up by virtue of the shape of the lower surfaces of the block where meets up with the valve stem (#17). It has a camming action, and if the surfaces of the lower corner of the block get worn, it may not want to stay up.

[UnGe]

Yep, #17 was my suspect, as it has signs of wear.
As the breech is able to stay up when the gun is pumped, I tried to extend valve spring, but it did not change anything.
I do not have problems with manually raising breech after cocking, but once in a while on the way up (pressing on the valve?) it causes some air loss, which is obviously not fine.

[UnGe]

It's been a while since I was inside one, but I think it stays up by virtue of the shape of the lower surfaces of the block where meets up with the valve stem (#17). It has a camming action, and if the surfaces of the lower corner of the block get worn, it may not want to stay up.

Thank you, as usual, the most correct info is coming from you :)
I tried to flatten the lower block surface a little, but it did not help (I was concerned to file too much, perhaps not enough) :(

[UnGe]

An update. Looks like another thing that keeps the breech up is air pressure. Replacing valve seal fixed the problem for me.

[Brimfire]

@UnGe, I've got similar problems with my Izzy - breech block not staying up and hit or miss compression with varying fps on the times it does hold air. Cocking the breech block manually doesn't make much difference to the cocking process but a violent pump of the charging lever does get the valve to seat and hold some air

The piston seal looked ok but a partial strip down of the valve assembly showed up a valve spring that looked a little shorter than that of an example posted in another TT thread. A gentle stretch got the lost 2mm or so back but things were just the same afterwards.

I never removed the valve seal for a close examination in case I damaged it but there wasn't anything greatly amiss that I could see.

With the knowledge that replacing the valve seal sorted things out for you, can I ask where you got a replacement item from please?

Thanks in advance,
Brimfire.

[UnGe]

With the knowledge that replacing the valve seal sorted things out for you, can I ask where you got a replacement item from please?

I got spares loooong ago, while they were still sold.
Seal replacement actually did not help to keep the breech up for too long, now it is flopping again. Stretching spring did not last neither, and I was unable to find the one up to spec. Ordered a bunch of different springs that seem close, will try to replace some day.

[Brimfire]

Thanks for the info.

Looks like my Izzy has just become a paperweight/ornament until the world returns to some sort of normality. A crying shame as it stands head and shoulders above my other (admittedly older) 10m pistols and suited my skill level and needs perfectly.

[Gwhite]

I just checked eBay, and there are several people selling IZH breech & piston seals. Some are from Poland, which may be easier to get to Scotland than getting them from the USA.

[Brimfire]

Thanks Gwhite. I checked out a few places online including some in Poland but nobody lists valve seals unfortunately.

I got my hands on a clubmate's Izzy a couple of days ago and the spring tension for the breech block seemed much stronger on it. It wasn't a side by side comparison so maybe not 100% reliable but I'll get the opportunity to compare both his and my own Izzy in a week or two and take things from there.

Had to use my seldom shot Hammerli 480K2 in the Izzy's absence and, inexperience with it aside, I noticed a larger degree of shot cycle movement with it than the Baikal. Surely shouldn't be the case but it increased my already healthy respect for the "agricultural" Russki and made me miss it even more.

[PeeWeeDaddy]

IMG_1725.jpeg (27.48 KiB) Viewed 6002 times

Send it to Tim McMurray.
He will repair your 46m to better than new.
He has a valve he can install that will NEVER wear out.

If you don’t want to send him the gun check with Air Venturi about repair parts and repairs.

mac1airgunshop.com

[m1963]

Interesting video of the IZH-46M triggering action. Perhaps it will help others, in the future.

Triggering-
https://www.youtube.com/watch?v=cfgFG76DBGE

Full action-
https://www.youtube.com/watch?v=LoVekydiBRk

Trigger adjustment instructions...

[toddinjax]

IMG_1725.jpegSend it to Tim McMurray.
He will repair your 46m to better than new.
He has a valve he can install that will NEVER wear out.

If you don’t want to send him the gun check with Air Venturi about repair parts and repairs.

mac1airgunshop.com

WARNING! I sent my 46M to Mac1 and he had it for over a year and never did a thing to it. Multiple phone calls, BS excuses from him and angry words. Do not send anything to this guy. He will tell you he had a serious accident.... but he had my gun for 6 or 7 months before that happened. The only credit I can give him is that after a loud and angry phone call (not my general demeanor) he did after 14 months, mail back to me my untouched pistol.
I had sent this AP to him some 11 or 12 years ago to be "Mac tuned" and service was fine including fast turnover, so I didn't hesitate to use his services again. Huge mistake.