Mares Cyrano Evo HF problems

[DANILO020]

....Pls explain a bit better the problem.....does the piston get hooked up? can you pull the trigger and the gun doesn't fire? the trigget got stuck?

 

[Erasmus]

....Pls explain a bit better the problem.....does the piston get hooked up? can you pull the trigger and the gun doesn't fire? the trigget got stuck?

Hi, when i load the shaft it gets hooked up. However when it comes to pulling the trigger it does not fire. I tried to rotate the screw that is present under the trigger guard, but when I rotate it to one end there is no trigger movement (as if on safety), while if I rotate it to the other end there is trigger movement, but the gun still doesn't fire.....

 

[DANILO020]

...did you totally dismantle it when you cleaned it up? did you remove the rear loading valve?

 

[Gazz]

It sounds like either the inner barrel has rotated or the trigger pin is bent/damaged (or possibly both)

You need to depressurize the gun and remove the trigger assembly for further investigation. When you have removed the trigger pin housing shine a torch down and see if you can see the sear and if it is lining up straight. I have had this issue in the past with the normal cyranos.

 

[Erasmus]

Thanks you both for your contribution. When I cleaned it up, I did not dismantle the gun - I have never experimented with that yet, nor do I have instructions for how to do that. I had just limited myself to depressurizing the gun, and spraying lubricant in the hard to reach places.

Not sure how to remove the trigger assembly. Very grateful for your further help in this respect, if you may, please.

 

[Gazz]

I cant give specific advise as i have never used a cyrano hf, but the operating principles are all very similar.

This video from salvimar shows you how:


It might look different the the cyrano but i think you will find it has very similar parts.

Watch from 7:20 and you can see someone dismantling the trigger from a normal cyrano (but not in english).

 

[popgun pete]

Assuming that the Mares schematic for their “Cyrano Evo” is reasonably accurate I decided to check out the swing of the trigger and the line release lever and sear lever activation sequence. You can see from the diagram that on paper at least the line release lever will be freed well before the sear lever is tipped over to the point where the sear tooth clears the bottom edge of the piston’s mushroom head tail. So there should be no problem with synchronization whereby the gun is shooting before the line release is able to swing in order to let go of the line wraps on the gun. However it would appear that the mushroom head tail can push past the sear tooth before the tooth is completely clear of the tail’s periphery and that situation will depend on the changing contact angle between the tooth face and the adjacent flange of the tail as the sear lever progressively tilts forwards and downwards at the front end.

 

[Jinggo]

I

Hi all from Libya. Well about 3 months ago I bought a Mares Cyrano EVO HF 90 and was working like a dream. I had to go abroad for a few weeks and cleaned the gun really well and sprayed WD40 over the all important parts. I also left it fully pressurized, but unloaded. After I returned (3 weeks or so), I went for a dive, loaded the shaft and missed two good shots because the gun wouldn't fire. I figured there might be some kind of dirt, and eventually depressurised the gun completely, blew pressurised air into the trigger area just in case there was some dirt, and gave it a few shots of WD40, and pressurized it again. I didn't try it out as I was on land. Yesterday I went diving again and the gun would not shoot. I took a screwdriver with me and turned the sensitivity screw in various positions, but the gun, although pressurized and loaded, will not fire even when the screw is set to the position which allows the most trigger travel. I am stumped - what could it be - I don't trust any workshop here in Libya to do any repairs - and prefer to do it myself. Any ideas guys?

Thanks.

I own cyrano Evo HF 100. Use couple times but now the trigger get stuck its look like safety never release...even the locking in normal position the gun still can't fire...anyone can help me to resolved this problems? Sorry I'm new in this forum.

 

[Jinggo]

Anyone can advise me the size of transmission pin or where to buy....website address?

 

[popgun pete]

Probably a bit late now, but some of the answers can be found here:
file:///C:/Users/admin/Downloads/Mares_catalogue_2016.pdf
For example the transmisson pin is 1.5 mm diameter, see page 141 in the catalogue.
I have been looking for some good photos of a "Cyrano Evo" opened up as distinct from a video, as I need to gauge the positions of certain parts without having them moving around in front of a video camera, which tends to be distracting.

 

[popgun pete]

I finally had a chance to slow-mo through the Mares "Cyrano Evo" video and check out why the gun had some problems. The tilt on the sear lever commented on above is due to the mushroom head on the piston tail having a fatter shank diameter than before which means when hooked on the sear tooth the lever has to sit at an angle and not be horizontal. That is because the top of the tooth is already hard up against the shank and the lever cannot level out. To further exacerbate matters the mushroom head has a rounded periphery said to aid a smoother release action, but what it does do is with the sear tooth face already slightly angled the piston tail can escape without you pulling the trigger!

How to fix this problem? Well Mares should have used a new sear lever with a lower tooth height so that when the top of the tooth hit the mushroom head's tail shank the sear lever was level, or horizontal, and then there would be no angled vector component as the opposing vertical faces, i.e. mushroom head flange and sear tooth face, were strictly perpendicular to the axis of the inner barrel. But they did not do that and that is why the gun can fire prematurely thereby "taking out" the line release lever by busting it. And to think that this gun got by the people who sign off new designs without anyone saying "we might have problems with a hooking mechanism that is not truly perpendicular to the direction of thrust"!

 

[popgun pete]

In fact the sear lever cannot work reliably at a greater tilt, or inclination, as the piston will be driven backwards with the sear tooth being depressed by pulling the trigger. Any slight angling of the sear tooth face created by machining it away from the vertical will tend to minimize this rearward pushing, but will then destabilize the sear lever's ability to hold the piston. The attached diagram shows this effect. A fix would be to use the piston from the original "Cyrano", or use its shank on the "Cyrano Evo" piston. Why the new piston has a thicker shank I don't know, but a reduced diameter shank (and mushroom head) on the piston tail would fix the "Cyrano Evo" gun.

 

[popgun pete]

This "leveled up" sear lever and reduced shank diameter for the piston is displayed on a proposed re-engineering of the "Evo" frame, or hull form, for a "Mirage" reboot, albeit one with improved internal breathing or airflow over its somewhat "strangled" predecessor.

 

[popgun pete]

This is the "Cyrano 1.3" piston used in the metal trigger guns with the blue handle. You can see Mares have squared up the metal piston tail as there is no bevel on the leading edge of the mushroom head.

 

[popgun pete]

A comparison of the rear grips is shown here.

It appears that a bump inside the trigger finger guard has disappeared that used to sit directly under the plastic fore-aft adjustable two-piece trigger and if that has been changed then this will be a new molding used in the later gun.

 

[popgun pete]

The importance of sear lever tilt is shown here, you don't want any tilt with the gun latched. Or else the gun shoots with the slightest trigger movement, which means busting the Evo''s line release lever.

Note the drawing with the green tick has been altered by me, the one above ii is the Mares original for the Cyrano Evo.
To drop the sear lever rear end to be more horizontal Mares could have either shortened the trigger transmission pin or wound out the trigger sensitivity screw in the back part of the plastic trigger. Pretty sure they have used the same sear lever in all their guns judging by the part numbers, but the transmission pin changes for the later blue handle guns as it has a different part number to the one in the Evo.

Note that with the gun discharged high internal air pressure inside the gun is acting on the trigger transmission pin and with the vertical coil spring tension is always pushing the sear lever's rear end to its lowest position in the gun ready for the next relatch.

 

[popgun pete]

As a matter of interest in the early days of band guns they mostly used single piece triggers and when they piled more bands on the gun the trigger closing torque was so high they could barely pull the trigger with say four or five bands on the gun. A fix to make the trigger pull lower was to file the tooth to a slight angle and then the trigger pull was less as in a sense the trigger was already partly pulled. This modification plus inevitable wear on the tooth moved the gun into dangerous self-firing territory where when you dropped the last of four wishbones onto the shaft it took off out of the gun. Now the safety, if the gun had one, became the new trigger! One can imagine such guns became very scary to operate with an errant shot sending someone to hospital and the gun owner maybe to prison. A pneumatic gun's safety only blocks the trigger, so will do nothing to stop the see saw action sear lever from turning, so filing sear lever teeth on such guns is dangerous. Why this single piece trigger type of sear lever avoids wear problems in a pneumatic gun is because it is swimming in oil, unlike the situation in a band gun.

 

[popgun pete]

When Mares installed the sear lever to sit at an angle it was the equivalent of filing the sear tooth to a slight angle, and all their problems stem from there. All side mounted line releases close coupled with the upper part of the trigger need to be checked for synchronisation of the release action. To do that you need to cock the gun at the pressure you will be using the gun and place the gun vertically with the spear pushed into a block of wood on the ground. You then hang a separate loop of shooting line with a weight on it like a lead fishing sinker on the line release lever, then bracing with your full body weight against the gun pull the trigger and control the gun rising up on the shaft. The weighted loop of line must drop before the spear is released. If it drops before then you will have problems. Wind out the trigger sensitivity screw a turn or two and then try again to get the line release happening before the piston unlatches. Because factory assemblers don't check for this you need to do it yourself. As the force level from gun operating pressure determines the opening action on the sear lever tooth you need your usual gun pressure for this test, not just a few psi in the gun.

Make sure you completely master how you do this, loading guns on land is very dangerous, keep tight control of the gun and point it downwards immediately it is cocked to shoot. Don't trust the safety, it only blocks the trigger, not the sear lever.

 

[finley97544d@]

When Mares installed the sear lever to sit at an angle it was the equivalent of filing the sear tooth to a slight angle, and all their problems stem from there. All side mounted line releases close coupled with the upper part of the trigger need to be checked for synchronisation of the release action. To do that you need to cock the gun at the pressure you will be using the gun and place the gun vertically with the spear pushed into a block of wood on the ground. You then hang a separate loop of shooting line with a weight on it like a lead fishing sinker on the line release lever, then bracing with your full body weight against the gun pull the trigger and control the gun rising up on the shaft. The weighted loop of line must drop before the spear is released. If it drops before then you will have problems. Wind out the trigger sensitivity screw a turn or two and then try again to get the line release happening before the piston unlatches. Because factory assemblers don't check for this you need to do it yourself. As the force level from gun operating pressure determines the opening action on the sear lever tooth you need your usual gun pressure for this test best diamonds veneers, not just a few psi in the gun.

Make sure you completely master how you do this, loading guns on land is very dangerous, keep tight control of the gun and point it downwards immediately it is cocked to shoot. Don't trust the safety, it only blocks the trigger, not the sear lever.

Thanks for sharing.