Registered User
Trying to get a usable amount of power out of an old mk6 airspoerter. I’ve currently fitter the size of o ring that is fitted to the meteor. And it is a looser fit than the airsporter one but how tight/ loose should it be. Also lubrication… how much silicon oil? Does it need to rotate free and easily in the groove of the aluminium head. I’m currently getting around 7ftlb as it is at the moment. Up from 4ish with the airporter oring. I wonder weather to try a size down again? I only lubricated the Irving with a bit of molly so that might not have helped. Any suggestions?
Last edited by hollow-point; 13-08-2024 at 07:33 PM.
tx200hc mk3 v-macheds400k in tawnado stock tuned qb78dlx hw100kt
Go ahead,,, String that bow
This vexes me because I have a Mk6 which is too tight. Many people say try a Meteor o ring which will stretch. This involves O ring crush and others more knowledgeable than me can describe it. How much the O ring is squeezed against the cylinder to give the best seal ( and least friction).
I've had one seal so tight I could barely push it down.
You could try a Meteor seal or let the Mercury seal bed in. I intend to try one some time.
The more I think I know, the more I realise the less I know.
Registered User
Sorry I put mercury when I went meteor. I’ve edited the post now. I’ve actually got a meteor o ring in there and still only sat in the high 6’s/ lower 7’sOriginally Posted by Dornfelderliebe
tx200hc mk3 v-mached
Go ahead,,, String that bow
I would not go any lower than the Meteor o ring.
You need to know how well everything seals.
Be very careful if you do the following check.
Cock the gun and open the tap as usual leave it open. Hold the gun by the pistol grip and with your other hand , cock it a little bit more so that it is off the sear Hold onto the cocking lever very firmly. To take the tension up.
Pull the trigger and release the tension on the lever slowly BUT hold it.
Now the cocking lever will return to it's normal position. How fast it does shows how well it seals. Mine used to hiss air out the the tap sides.
My Mk1 &2 sporters take noticeably longer to return.
If you don't feel fully confident don't do. I have a bent wedding ring and two previously broken fingers* when my Mk5 sear failed and I left my hand in the way.
* the ring stopped it being four.
The more I think I know, the more I realise the less I know.
Registered User
The first thing I would do is hand slug the comp tube with 400 grit then look at the fit of the O ring and if tight deepen the undercut in the piston head to size it , If you have a lathe it is a easy job to leave out the buffer washer and long stroke the action up to a whopping 70mm and it will shoot better also when you have got the piston running faster the air has less time to leak out the loading tap .
Registered User
Being an o ring seal it will always have resistance. You should be able to push the piston down the bore comfortably with your finger on the latch rod. You mention silicon oil, be very careful as some silicon oils cause metal on metal to tear each other apart. I only tend to use moly grease in mine. Also, you don't say what spring you have used in yours, due to the short stroke they need a reasonable spring to perk the power up.
Plinkerer and Tinkerer
Registered User
What Spring are you using? where did you get the O-Rings and buffer washers from?
Registered User
There are kits available from here ; https://www.trrobb.com/product/bsa-m...er-piston-head
Other version https://www.trrobb.com/product/bsa-a...ke-ssteel-head
Or there is this https://www.woodfield-gcp.co.uk/shop...al-adapter-kit
Personally I wouldn't take 400 grit to the chamber, it'll raise the surface for a short while and it will also make it rough enough to eat the seal too.
If it's not just the seal (is the breach seal ok ?) then it has to be the spring.
There are threads on tuning later models of airsporters on here, it involves fitting a shorter piston head to gain more chamber volume, this increases the power enough to even cut a coil off the spring for a softer cycle apparently.
Admin's pet.
Welsh willy does a piston head that uses a diana 28mm seal .....got one to put into my carbine
them there springer's are soooooo addictive
Go ahead,,, String that bow
I would second that. I put one in the Mk5 Airsporter and it worked reasonably well then put another in a Mercury and it worked wonders.
My Mk6 Airsporter feels like it's seizing up so I shall give up with the O ring. An aussie seal 28 mm conversion WILL now go in that.
The more I think I know, the more I realise the less I know.
Admin's pet.
You might need a spacer using that aussie one .....long strokes it a little bit too muchbeen measuring it up as I have one here too
Go ahead,,, String that bow
The piston in question which I broke a tap in and is now with Meden vale engineering to put right, already has the slot lengthened.
It is the victim of the worst case of piston lightening ever perpetrated but I'm hoping it will be ok with .177.
The more I think I know, the more I realise the less I know.
Admin's pet.
Keeping the breed running is paramountThe piston in question which I broke a tap in and is now with Meden vale engineering to put right, already has the slot lengthened.
It is the victim of the worst case of piston lightening ever perpetrated but I'm hoping it will be ok with .177.
Registered User
Your next problem with the Airsporter may be that of running out of leverage. The underlever will hit the trigger guard before the sears lock upThe piston in question which I broke a tap in and is now with Meden vale engineering to put right, already has the slot lengthened.
It is the victim of the worst case of piston lightening ever perpetrated but I'm hoping it will be ok with .177.
Registered User
The spring is a chambers standard. As is the buffer washer. The o ring in one I ordered from the internet. I ordered the standard airporter size and the mercury size which is one smaller. I forget the sizes just now but one was 11 and the other 10
tx200hc mk3 v-mached
Posting Permissions
Reply With Quote