Bsa spitfire hf

[Diddydave]

Advice needed i inherited recently not used for ages could pump upto 50bar with hissing from barrel have resealed with kit now will pressurise to about 60-70bar and let go of air to enough for couple of shots that’s it , can anyone shed some light

[TVRGREG]

Sounds like it needs a new valve stem if you have not already fitted a new one.

[Diddydave]

Seal kit cam from knibbs part list is 10 but get 12 parts in kit even they were unsure why ,you get a violet plastic type seal about 4mm thick 9 mm diameter and take it that’s new type valve as nothing else like it inside

[MartynB]

Advice needed i inherited recently not used for ages could pump upto 50bar with hissing from barrel have resealed with kit now will pressurise to about 60-70bar and let go of air to enough for couple of shots that’s it , can anyone shed some light

John Bowkett designed them, perhaps ask him

[TVRGREG]

I have not worked on a spitfire yet, most seal kits don't come with a replacement knockoff valve stem.
maybe the violet plastic part is for the fill valve.

[deejayuu]

It may be the exhaust valve head taper too wide. Can happen over time. The synthetic conforms to brass seat over time. JB suggests facing to ninety degrees.
Worked on ours. Don't know if it was a problem though 'cos ours wasn't holding at all when arrived.

[Diddydave]

Thanks for the advice guys, def something to try the old k/0 valve was black and about 5mm thick by 6mm diameter the violet part has helped as no more hiss from barrel just can’t get it to hold air past 60bar annoying thing is I made one out of car vacuum hose and would hold upto 90bar then blow past deforming the rubber so am sure gotta be k/o valve at fault

[deejayuu]

Check that face angle.