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Leaking carbs!

Posted: Mon Jul 12, 2010 1:11 pm
by Will Reeve
4 weeks "dry" didn't do my twin SU's much good, on first start they spilled fuel out the bottom! The only think I didn't end up at least doing a little re-furb on let me down....a lesson there me thinks!

Posted: Tue Jul 13, 2010 9:30 am
by kiwicar
In my experiance SUs are simple to sort out with a rebuild using the kits as supplies so I am beginning to think you may have one or more cracks in the body, worth a check around where the float jet screws into the float chamber. the other thing it could be is a leaking float worth a check as they have been known to fall appart.
Best regards
Mike

Posted: Tue Jul 13, 2010 1:15 pm
by Will Reeve
You know how to worry someone! Luckily it was just the 'o' ring at the bottom, float and all internal stuff looked nice and clean. That rubber 'o' ring was like plastic.
I don't think they liked being dry on the bench for the last few weeks. I guess they have had petrol in them for the last 30 years or so! I checked for cracks and visually they looked OK. Ran the fuel pressure up with the pump and no-leaks as far as I can smell.
There seems no "pressure relief" in my system, the fuel pump just slows to a chug when the pressure builds up. I guess it's designed like that without a pressure regulator.

Posted: Tue Jul 13, 2010 2:07 pm
by kiwicar
Hi
Glad to hear it is not serious, just when you posted up saying you were still having trouble even though you had refurbished the carbs. . . the O rings will perrish after 30 years, especially when exposed to petrol, letting them dry out for 4 weeks won't have made any difference.
Best regards
Mike

Posted: Tue Jul 13, 2010 2:14 pm
by Will Reeve
That's my English! I meant the only thing I didn't touch was the Carbs, just pulled them off the manifold, put them on the bench, and bolted them back on!
The disappointment of 10 hours to get the engine finished and in the car at the weekend only to be scuttled by a fuel leak was great!

Posted: Wed Jul 14, 2010 4:58 am
by minorv8
Hose quality today is another issue. Visually they look good but once you have fuel pressure there are nice leaks. And this with relatively new hose.