General Sudden carb leak

[Highland jamck]

Afternoon…. Just in case anyone has thoughts, been on a short jaunt today and coughed to a halt after a few miles. Opened the engine lid to help it cool and I find there’s a fast drip of fuel off the pipe I assume is designed for the purpose at the base of the carb. I tried tightening a couple of screws/nuts I thought might be relevant, but although it did start again briefly, so did the leak. I wonder if something is stuck inside the carb as it has been well behaved until now, but any thoughts appreciated. For now I’m getting value out of my local recovery service via the insurance policy!

 

[fiat500]

Afternoon…. Just in case anyone has thoughts, been on a short jaunt today and coughed to a halt after a few miles. Opened the engine lid to help it cool and I find there’s a fast drip of fuel off the pipe I assume is designed for the purpose at the base of the carb. I tried tightening a couple of screws/nuts I thought might be relevant, but although it did start again briefly, so did the leak. I wonder if something is stuck inside the carb as it has been well behaved until now, but any thoughts appreciated. For now I’m getting value out of my local recovery service via the insurance policy!

Hi John...I did see you message. There is a chance that the float inside the carb is stuck, out of adjustment or damaged. It's like a ballcock setup in a cistern. Your plugs may be blackened by overfuelling.
In order to verify this you would have to remove the top off the carb. This is easiest when the carb is off the engine. It's a fiddly job, but many times easier than on a real car. Please see this thread....

Carb leaking | FIAT 500 (Classic)

My carb is leaking from this pointy drain at the base of the carb, enough to ruin the paint below. Engine is running poor, hard/impossible to start after cold start ....stuck float?? Little bit of gas in the tray below carb also. Plugs black and a bit wet. Also noticed a drop of oil coming out...

www.fiatforum.com

 

[Highland jamck]

Thanks Peter …. I’m still emotionally scarred from sorting out reverse gear, but I’ll look further into this in the week sometime

 

[the hobbler]

Thanks Peter …. I’m still emotionally scarred from sorting out reverse gear, but I’ll look further into this in the week sometime

I agree with Peter---the first thing that I would look at would be the float. The top cover of the carb CAN be removed with the carb still in place--a (very!) small ratchet spanner and one of the little screw-driver 'inserts' being the best tool. Give the float a shake--if it 'ratttles, there will indicate that there is fuel in it, and you will have to replace it; they can't really be repaired. Before you re-fit the carb's top cover, you will have to make sure that the float is adjusted corrctly, again, not a difficult job.
When the float has petrol IN it, the float will then weigh more than it should, will not float and won't rise and shut-off the needle-valve, and therefore allowing excess fuel into the carb

 

[Highland jamck]

Thanks very much, will also bear this in mind when I take a proper look - I am a simple soul so simple solutions attract..

 

[smart51]

I have a tiny screwdriver that is ideal for removing the carb top in situ. There's a photo here: https://www.fiatforum.com/threads/correct-jetting-for-594cc-engine.504490/post-4713437

They're £3.99 on Amazon https://www.amazon.co.uk/gp/product/B09W5D5SW9/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[Highland jamck]

looks like a useful little thing. Was also looking at slightly more extravagant mini set
Bosch 27pc.Screwdriver Bit and Ratchet Set (PH-, PZ-, Hex-, T-, S-Bit, Accessories Drill and Screwdriver)
https://amzn.eu/d/5kY59t8

 

[the hobbler]

looks like a useful little thing. Was also looking at slightly more extravagant mini set
Bosch 27pc.Screwdriver Bit and Ratchet Set (PH-, PZ-, Hex-, T-, S-Bit, Accessories Drill and Screwdriver)
https://amzn.eu/d/5kY59t8

The tool that I have is identical to the "mini-ratchet" sold by 'Sabrecraft'

 

[Toshi 975]

My tiny set from Halfords, sooo useful especially when I fit a small 8/10mm sockets and spanner in the box.