Difficulty determining correct o-rings for older Mares pneumatics

The kits are still available for the Cyrano and Spark which is also the Sporasub Stealth. Cyrano had the snout and the other two had the usual front bulkhead or nose cone which provides more tank volume than Cyrano guns of the same length. Just to confuse users there is also a Sten 11 which is a renaming of the Spark.

popgun pete said:

The kits are still available for the Cyrano and Spark which is also the Sporasub Stealth. Cyrano had the snout and the other two had the usual front bulkhead or nose cone which provides more tank volume than Cyrano guns of the same length. Just to confuse users there is also a Sten 11 which is a renaming of the Spark.

Mares Service o-rings Kit for Cyrano, Sparks, Stealth | eBay

Pneumatic spearguns need to be serviced regularly to ensure that they are in correct working order. The Mares o-ring kit is for use when servicing Cyrano and Spark Pneumatic Spearguns.

www.ebay.com.au

View attachment 60174

Click to expand...

Yes, the kits are still available and much cheaper here in pneumatic gun country but I don't know for how long. Mares does not longer manufactures spares for my older Cyranos. Even here in Italy I could not find the barrel for the 850 and the search started with Mares factory and extended to every shop in the country. Same for the handle blue cover or the complete handle. I got the seals for this change but for spares I rather have Viton than the NBR found in kits. I don't like NBR's greater tendency to acquire permanent deformation, the limited shelf life and rapid deterioration if exposed to light, even fluorescent. On deep-water drilling oil rigs we have tons of very expensive NBR used on BOP seals and they are kept in a special rubber only storage room with infrared light only. I just bought a brand new Sten 2001 gun handle and the O-ring on the power reducer was broken by just sitting on the shelf (by the dust cover for a fair amount of time). The way they pack the seals kit is not ok either. They should be in black or reflective bags. When you buy the kit you just don't know what you getting, how old are they? where have they been kept? Except on price Viton is far better in all departments and with the price of that kit on ebay you can make 10 kits in Viton. Hopefully I will find a suitable ring for the tank as replacement of 46110208. I did a test using Solidworks software DIN 3771 O-ring and grove selection feature and the correct size O-ring for the tank seal should be CS 2.65 x 32.5 with a grove 34.1 mm dia. That diameter is 0.7mm smaller than the actual one and would leave the hollow plastic bulkhead too thin and weak in way of the grove. As there is little money in seal kits I wonder why they just did make the bulkhead beefier and use a standard ring. I will try find out but given the 30+ years time lag I suspect there may be no memory on the why. Do you know what they have been using on the guns after the first series Cyrano? If the bulkhead and O-ring stay the same it may be about not wanting to make new tooling for the bulkhead manufacture. The bulkhead is very thin and I would caution against trying squeeze in a too fat ring that may crack the plastic. I would probably first try with stretching a Viton ring or just get a bunch of 46110208 and store them properly for years.

I think Mares has moved production from Italy for some items. A few years back many speargun components were coming from Estonia as spare parts, such as inner barrels and tanks as well as the smaller items, you could buy them all on eBay. Now these same parts are coming from Lithuania on eBay. Many years ago Mares dive fins were being made in Eastern Europe and with lower labor costs the other items will no doubt have followed. The Sporasub Stealth had parts made in Asia and assembled in Italy according to Russian sources at the time, Sporasub was then owned by Mares before going to Omer. Omer's pneumatic guns were made in Taiwan, but have since been discontinued, they were nothing to write home about, but better than nothing.

Check this out.

The main body ring that fits on the nose cone, power regulator block and rear handle has been the same for as long as I can remember and dates from the first Sten series. They are for guns with 40 mm tanks. The body rings were different on the Titan models which were mid-handle non-floaters.

The double front bulkhead and nose cone on the earliest Cyrano has an extra smaller ring between the two parts.

Need Help, I am opening my Mares Cyrano 970, pre evo series, how much fork oil does it require?

Spear Gulf said:

Need Help, I am opening my Mares Cyrano 970, pre evo series, how much fork oil does it require?

Click to expand...

About 30 cc or 30 ml.

popgun pete said:

About 30 cc or 30 ml.

Click to expand...

Thanks