Flooding carb issue

[Captain Mike]

Hi all

I have a flooding carb on my mk1 ruby, gushing out of the hole on the top of the carb, I have removed the carb and checked to make sure the float and cut off needle are working and all seems  well, however before this started I replaced the diaphragm in the fuel pump

Could the pump pressure be overcoming the float needle seal ? 

Ideas and suggestions welcome

Thanks

Mike

[flywheel1935]

Drop the needle valve with a thin fibre washer, mine did the same on my ARQ Ruby until I did the washer job.

[Captain Mike]

New to the zenith carb

is there a schematic showing the needle vale ?

Thanks for the advice

[nrzam]

Did you by any chance put in a different spring when you replaced the diaphragm? If so, try putting the old one back in.

Ian

[Captain Mike]

Hi Nrzm

I fitted a new spring that came with the diaphragm and I am suspecting this may be the issue, I did add fiber washers to the float needle and the carb body but it did not make any difference, this was around 3mm
I will be fitting the old spring in the pump tomorrow and will report back

Cheers
Mike

[nrzam]

I had the same issue you described and it vanished when the old spring went back in. Nothing else required. Hope you have the same result!

Ian

[Captain Mike]

Still having the same issue I thought I replaced the pump spring but the diaphragm did not come with a new spring,replaced thr old diaphragm and tried again still flooding badly, needle jet does not pass when blowing through it will try more washers under the needle valve, does the fuel cut off rely on the floated needle vale or does it resurculate within the pump also somehow?

[Reckless Rat]

If the needle valve isn't seating properly it won't create the necessary back pressure in the line back to the pump to cause it to idle. Try taking the needle valve out and give its point & seat a polish with some fine paper. Are you sure the float is OK?

[Captain Mike]

Checked the float not leaking.used some metal polish to clean the float needle and seat,added a washer under the float needle all not worked,thinking of installing a valve betewthe pump outlet and the carb inlet to sè if I can control the flow as it seems too high
Frustrated from Nottingham!

---

Well you live and learn!
Cleaned up the thread on the float needle and lightly sanded the shoulders, then lightly sanded the carb body where the float needle screws in and it has stopped flooding!
The simple things first!
Happy camper
Mike

[John Mason]

I had this problem after stripping and cleaning my carb. I had a spare aluminium washer that I put under the valve which cured the problem but I can see no reason why a fibre washer should not do the same thing.

John Mason