PCP tuning wizards help

[mark1]

I have an old falcon FN12TW rifle .It has a welham reg which has unfortunatly started to leak,im not complaining its well over 10 years old and money well spent,the problem is im trying to get the gun working again for my 9 year old son on a tight budget so i have removed the reg ,replaced the O ring and stopped the leaks ,before you ask the tube was not vented.
I have machined a threaded spring retainer to keep the valve closed however the rifle does not function to say its inconsistant is an understatement.
fully charged its producing 2ftlb and flat about 16ftlbs
i think the problem is with the valve return spring being too strong, because when the gun was regged the pressure behind the valve would have been much less so the spring would have to compensate for the lack of pressure to counter act the hammer spring
your thoughts please
if i was paid £1.00 for every time iv stripped this bugger i would have a lot of pounds

[ora8i]

Sounds like you need parts.

With the reg out of the picture (why not fix it ?) the rifle should be standard except for the valve and hammers springs.

So just get on to AA/Falcon and replace both, the cost should be low.

Why do you need a part to keep the valve closed the air pressure + vave spring should do that?


Regards Ora

[mark1]

because the valve and retaining spring are not standard ,the reg has been screwcut into the brass section and it also held the valve return spring in place,i think a reg service would cost around £100 and at the moment it might as well be £10.000

[ora8i]

Ok that makes sense.

Would it be possible to strip the reg and use the section that pre-loads the spring? You know that when fitted it worked and the valve had been balanced for a lowish inlet pressure (reg outlet pressure).


Really the big question is, are there any other mods? to the Air path/exhaust port anything at all.

It might be easier to try to get a complete valve second hand.

Ora.

[mark1]

because the brass section has been threaded to take the reg i dont think a standard valve/assembly would go back,i coppied the rear end of the reg to retain the spring in place but the spring is very strong ,s can only get the valve open with a very heavy hammer spring,its very frustating as the gun has to be completely stripped each time at the rate im going it might be easier to make a super short air resovoir,as i typed that iv decided to forget that idea as it would be too dangerous