94' Royal Enfield Bullet 500 Fuel leak From carb

[piratebiker]

Got a fuel leak from base of carb, see image. How can I fix this? Thanks.

[stinkwheel]

That's an overflow. Either your needle valve is damaged/dirty/blocked or the float is punctured.

Hitchcocks do a service kit for those carbs. They are a mikcarb, a licenced copy of a mikuni. The kit has all new brass parts and seals up to mikuni spec. They improve the running of even a new mikcarb (especially at idle) and yours is 25 years old. The kit includes a new needle valve and seat.

I'd suggests stripping and cleaning the carb and fitting a service kit.

Also check the float. If it has fluid in it (shake it next to your ear) or sinks/floats unevenly on water, it's burst and needs replacing.

If you have a performance exhaust/air filter, you may have different jetting on your carb so check what's in there as you strip it, they should have numbers stamped on them.

I would be the last person to suggest using kitchen equipment for motorcycle parts however, if you strip the carb, the body and float bowl will come up lovely after a run through the dishwasher.

If you're short on funds, try cleaning the needle and seat and check the float but I'd budget for replacing the needle valve and seat. The needle has a rubber ring on it which may not have been ethanol proof in 1994, a new one will have a viton sealing ring.
https://accessories.hitchcocksmotorcycles.com/1837?qty=1&continue_url=https%3A%2F%2Fwww.hitchcocksmotorcycles.com%2Fpartsbook-pages%2F1621
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[piratebiker]

That's great, thanks.

[piratebiker]

Hi, how is the overflow valve removed, there's a Black plastic cap but can't get that off? Is there an O-ring that can be replaced as not confident dismantling the carb. Thanks.

[Polarbear]

Does this help?

https://www.team-bhp.com/forum/attachments/motorbikes/43254d1220002094-help-carburetor-bullet-500-rd-350-rd350carb.jpg
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Triumph Trophy Launch Edition

[stinkwheel]

You wouldn't normally remove the overflow. It'll be attached to a pipe on the inside of the carb and is almost certainly a very tight push-fit. The plastic bit may well be glued on.

The overflow isn't a valve, it's just a pipe in the bottom of the carb. If the fuel level gets too high, it reaches the top of the pipe and fuel runs out of it. Exactly like the overflow on a toilet cistern Nothing there to go-wrong and there should be no need to remove it.

You need to fix the reason stuff is coming out of it which will be something in and around the vicinity of the float or needle valve as previously discussed.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[WD Forte]

Not sure if relevant, but it reminds me when I found some old CX Carbs
where the overflow pipes made from very thin brass
had rotted and split over time.

I got some brass tube from a moclel shop and
after some Dremel jiggery pokery JB-Welded new ones in.
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bikers smell of wee