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Diagnosis? Fuel leaking out of Dellorto air trumpet

PostPosted: Tue Mar 15, 2022 4:24 pm
by rodsandyachts
Hi Gents

My daily driven and occasionally tracked Plus 2 S has fuel leaking out of the rear air intake trumpet on the Dellorto. This happens while parked with engine off and leaves a fuel puddle on the ground so it's quite a big leak.

It's almost certainly related to a driving fault I've noticed. When parked hot or idling at lights, the engine tends to flood (I think only the rear cylinder). A few blips of the throttle pushes out some black smoke and then it runs in tune (not rich).

What's happening to my rear carb while parked and at idle? Diagnosis much appreciated.

Many thanks
Simon

Track.jpg and
Carb.jpg and

Re: Diagnosis? Fuel leaking out of Dellorto air trumpet

PostPosted: Tue Mar 15, 2022 6:14 pm
by Bitsilly
I would guess that the floats are not stopping the fuel correctly.
That said, in the history that came with my car, it was sent in to a garage to have that same problem fixed, so I will check and get back to you unless someone cleverer than myself gets there first.

Re: Diagnosis? Fuel leaking out of Dellorto air trumpet

PostPosted: Tue Mar 15, 2022 6:21 pm
by Bitsilly
Sorry, no explanation was given.
I have a stripped Dellorto here so if you want any parts (free) pm me and I'll check.

ps.have you tried removing the rag?

Re: Diagnosis? Fuel leaking out of Dellorto air trumpet

PostPosted: Tue Mar 15, 2022 6:36 pm
by Donels
It sounds like the carb is flooded, so the float is probably punctured and not shutting the valve. You are probably overfilling the rear cylinders all the time, but you only notice at idle. Remove the top off the carb and check the float, replacements are available. It's probably leaking out of both trumpets.

Re: Diagnosis? Fuel leaking out of Dellorto air trumpet

PostPosted: Tue Mar 15, 2022 7:18 pm
by rodsandyachts
Great suggestions thank you all. I'll remove the carb cover and see what the float's doing. Will report back if it's of interest to others.
Thanks again.
Simon

Re: Diagnosis? Fuel leaking out of Dellorto air trumpet

PostPosted: Tue Mar 15, 2022 7:50 pm
by Donels
If not the float check the valve itself.

Dave

Re: Diagnosis? Fuel leaking out of Dellorto air trumpet

PostPosted: Sat Feb 24, 2024 9:44 pm
by Dellortofan
Any solution?
Float or dell drip scenario?