Airsporter RB2 troubles

[MattyBoy]

Hello all

I have dismantled my newly acquired RB2 Airsporter to try to fit new seals and spring.

I have the piston out but now I am not sure how to continue.

I can see an obstruction that looks like a grub screw jutting into the transfer port when I look down the cylinder through the barrel

Is this normal?

How do I get the ally breech out of the cylinder?

Is it required to drift out the pin across the cylinder that allows the barrel to be removed from the cylinder? This seems a bit radical to have to do just to change the seals on the rotating bereech?

All help gratefully received

Thanks

[Airsporter1st]

Hello all

I have dismantled my newly acquired RB2 Airsporter to try to fit new seals and spring.

I have the piston out but now I am not sure how to continue.

I can see an obstruction that looks like a grub screw jutting into the transfer port when I look down the cylinder through the barrel

Is this normal?


How do I get the ally breech out of the cylinder?

Is it required to drift out the pin across the cylinder that allows the barrel to be removed from the cylinder? This seems a bit radical to have to do just to change the seals on the rotating bereech?

All help gratefully received

Thanks

Looking at Chambers' drawing, it looks as if the rotating breech should slide down the cylinder (after removing the little knob that you use your thumb on to open and close it)?

I believe the grub screw is there to restrict the power.

[MattyBoy]

Thanks Paul for your useful insights

Now then...

How do I get the thumb lever off the rotating breech?



Thanks

[MattyBoy]

I'm stumped

Anyone?

Thanks

[flatrajectory]

From memory, the knob is held in by a flat piece of spring steel, so just wiggle and pull. Don`t loose the flat spring.

pete.

[MattyBoy]

From memory, the knob is held in by a flat piece of spring steel, so just wiggle and pull. Don`t loose the flat spring.

pete.

Hooray, you made my day mate

Thanks

[martini1215]

I must bookmark this post and remember you as the guy who has done it when I take mine to bits Matty
ATB Martini

[MattyBoy]

Hello again all

It's really that simple

I used a small plastic ruler slid under the breech lever and gently levered upwards.

The lever slides upwards out of its housing with the mentioned 6mmx6mm square of spring steel which is the retaining device.

Once this is removered you can push the breech block down the cylinder with you finger then use a dowel or similar gently to push it as far as possible down the cylinder, through the breech hole.

I then tapped the cylider gently veritically on a rag on the floor and out slid the block

The front O-ring was knackered and luckily I had 1 (just 1!) the correct size - it's 9mm OD with cross-section 1.9mm

The rearward O-ring sits in a groove around the circumference of the cylindrical block and is very fine in cross-section. This O-ring was in perfect condition so I did not replace it. Sorry but I did not remember to measure it with the verniers

I applied a very small smear of silicon grease to both O-rings and to the bearing surfaces at each end of the breech block.

Having cleaned the cylinder with a white spirit soaked rag on a pole I left it for a few minutes to dry then reasembled with a new old-stock airsporter spring with all the approriate lubing etc.

When I got this baby she was doing 9 ft lb and was very twangy due to being completely dry inside.

After the re-build she is now very smooth with no twang and shooting at around 11.00 ft lb

Job done

[air-tech]

That's great Matt, have also saved this page for future ref

[MattyBoy]

If I find time today I'll copy this into the Idiot's Guide and elaborate a bit

Cheers

[Airsporter1st]

If I find time today I'll copy this into the Idiot's Guide and elaborate a bit

Cheers

Glad you were successful.

They're a great gun and I particularly like the breech loading system - one of the safest and easiest to use.