Stromberg overhaul problem

[69S4]

I've just got a box of new bits in from Burlen fuel systems to overhaul my Strombergs, including new jets but I've hit a snag. I need to remove the screw on brass covers (one shown in the pic below) to get to them and nothing's moving. The screwdriver slot suggests it should just unscrew but it won't. By the look of the plumbers wrench marks around the top a po has gone to some lengths trying to get it to move but I'm a bit worried that the casting will break if I apply too much force.

Any suggestions as to how to proceed?

[oldelanman]

Hi Stuart,
Soaking in Redex has been recommended on here in the past for dissolving fuel deposits, you could try that.

If that doesn't work try the thermal shock treatment. Place the whole thing in the freezer for a while and then in boiling water, repeat that a few times and then give it a go.
Good luck.

Regards,

[ppnelan]

A 2 pence piece fits nicely in the slot if it is undamaged, with mole grips clamped on the coin. I have found that the softness of the coin provides a 'failsafe' to avoid breaking the casting!

Matthew

[69S4]

Well I've got the first one out. I started out nice and gently - Mathew's 2p suggestion (I actually used a 5 euro cent coin, 2p was too wide) but it didn't move and I've now got a small collection of bent 5c's. Neither did boiling the carb body and then 5c-ing it. I was well into "I really shouldn't be doing this to a carburettor" territory - Mole grips around the end of the brass cover and heating the casting with a blowlamp - before it eventually worked loose.

I was expecting it to bring the casting threads out with it but it was fine and hopefully the mole grip marks should file out! Next task is to work out how to remove the old jet and press in the new one.

[oldelanman]

Hi Stuart,
Well done....one down, one to go.

[url]
http://faq.saabnet.ru/saab_carbs/6_misc.pdf[/url]

I posted this link once before you might find it helpful when replacing the jet - describes how to tap it in and gives the correct installed depth below the carb bridge. When tapping in the new jet you need a drift with a hole in the centre so you don't damage the orifice.

Gently does it. Good luck.

Regards,