Thread: Series 2a Carbie problem - fixed

Thought I'd post this in case it helps anyone.

A couple of days ago the 2a started refusing to idle without the choke pulled out a bit.

So yesterday I pulled the carburetter (Zenith) to bits to clean, and found no problems. Still no better. So this morning I pulled the PCV valve to bits, expecting to find a perforated diaphragm (it wasn't), and also checked the vacuum line was not leaking or the points closed up (neither was a problem).

After thinking about it, before lunch today I pulled the carburetter to bits again, checked in the book which is the slow running jet, and had a close look at it with a magnifying glass. Once I had dried it of petrol, it became clear that it was blocked by something transparent and hard, possibly a grain of sand. It would not dislodge with compressed air, but eventually, working under the hand lens, I was able to dislodge it with a needle without damaging the jet.

Reassembled it and now ticks over like a sewing machine only quieter. The idling mixture needed to be weakened a bit, suggesting that the jet had been partly blocked for some time.

I have no idea how it got there, as the fuel line has a filter on it. Best guess is that it came off my hand last time I had it apart, which was to lap flat the top cover a few months ago, and swished round in the bowl until it was sucked into the jet.

John

Well mate
my drain frogs have been singing a merry tune for a week now, plus they are all sitting in the carport now, the rain drove them from the gutters.
from what I saw on the news tonight there is a bit front coming across the centre of NSW,
so I hope it slowly soaks your end of the world, I think about 15mm a day for about a week should be a good start
we are a bit too green here at the moment, have to mow every 4 days, plus the ground is saturated and the tanks overflowing.


john