Walther Cp88 not indexing

[BSFNUT]

A friend has one of these as above.

I know nothing about CO2 pistols.

Anyone know if it's a seal issue or worse ?
Who repairs these ? the only guy I know is Lawrie Armatruda ( are they worth fixing or throwaway ?)

TIA

[ashf9999]

If it’s not indexing, then it’s mechanical. The CP88 (like a lot of Umarex pistols) cycles its round magazine by a pawl that’s activated by the trigger, kind of like a revolver. That’s not a seals issue.

It may be worth checking the magazine just isn’t worn, as they are alloy and they can wear with excessive use. Are there any other magazines to try before you need to get the screwdriver out?

You can get spares from the normal places, so the likes of TW Chambers etc, so it’s worth doing. It’s not overly fiddly - there are some decent videos on YouTube.

[EricP]

Also check that the pellets are seated correctly in the magazine, i.e the skirt isn’t protruding out the back, the nose isn’t protruding out the front, as that can stop the magazine moving. I use flatheads (wadcutters) they are better in the Umarex magazines
Eric

[ashf9999]

Also check that the pellets are seated correctly in the magazine, i.e the skirt isn’t protruding out the back, the nose isn’t protruding out the front, as that can stop the magazine moving. I use flatheads (wadcutters) they are better in the Umarex magazines
Eric

Yep, valid point.

[Geezer]

As those guys said, check pellet seating, and try newer cylinder-mags, as they do wear.

If that doesn’t help, it’s time for your friend or someone else to take it apart and start replacing the pawl or possibly other parts.

[evert]

Mine has the same problem, but I cant find any worn parts when taking the gun apart.
So I'll be watching this thread to see if you find any solutions.

[ashf9999]

Mine has the same problem, but I cant find any worn parts when taking the gun apart.
So I'll be watching this thread to see if you find any solutions.

Was the pawl spring still there?

[cozzamec]

It's probably the pawl, I had it with a rws c225, same mechanism, took it apart and I thought the pawl looked OK, until I compared it with the new one and could see wear, not loads, but enough to affect indexing

[Neil54]

It doesn't take much wear on the pawl to stop it indexing.
Sometimes a different mag will work.
Sometimes flat head pellets work best. seat pellets with magazine on a flat surface.

If your really really stuck, send it to me. I'll sort it at cost.

[evert]

Was the pawl spring still there?

Yes.

Too the gun out and tried it again. I see i have two types of magazines, with some minor differences in the indexing "knobs".
One type of magazine does not rotate, but i can pull the trigger, and the other kind hangs up the entire mechanism and locks the trigger.

I got the gun REALLY cheap, knowing that it didnt work right, and it would be nice to have it shooting before summer.
Seems like one of the Norwegian suppliers has spare parts, so I'll try a new pawl and spring if it is not too expensive.

[rapidresponse1]

mine only done it when pellet was sticking out

[evert]

It doesn't take much wear on the pawl to stop it indexing.

A new pawl fixed it!
The sharp corner of the original pawl was rounded

But now the valve has developed a slow leak...

[ashf9999]

A new pawl fixed it!
The sharp corner of the original pawl was rounded

But now the valve has developed a slow leak...

Leak is definitely from the valve itself? (not just the seal twixt capsule and valve?). If you are going to strip the valve itself, best off changing all the rings, not just where you think it leaked from. The thinnest (really virtually none at all) of smears of silicone grease on the seals before reassembling can help.

[evert]

Leak is definitely from the valve itself? (not just the seal twixt capsule and valve?). If you are going to strip the valve itself, best off changing all the rings, not just where you think it leaked from. The thinnest (really virtually none at all) of smears of silicone grease on the seals before reassembling can help.

Yeah, when I used a lubrication cartridge the oil came out of the valve front.
Probably needs new seals as you say.

[evert]

Leak is definitely from the valve itself? (not just the seal twixt capsule and valve?). If you are going to strip the valve itself, best off changing all the rings, not just where you think it leaked from. The thinnest (really virtually none at all) of smears of silicone grease on the seals before reassembling can help.

Took the gun apart again, and the O-ring around the valve exhaust stem was visibly damaged, which corresponds clearly with the leak I experienced.

Some years ago, I was given a wreck of a Umarex 586. It contained the same valve as the CP88, so I had another of these O-rings.
Changed it, careful not to damage any seals, and the gun now seals well, indexes and shoots, so success getting it to work.

Now the net problem arises it shoots way too high!
The rear sight is windage adjustable, but theres no height adjustment.
Are there different front blades for these?