Morris Minor Owners Club

Hi all

New to the Morris Minor and this site.

Have a problem with my 1963, 1000. Car drives great and is very responsive, problem is when it is just ticking over at low revs it runs really lumpy and is only happy when I pull the choke out and the revs go up. What could this problem be? I have replaced points and condenser.

As you can tell by my description, don’t know much about the oily bit on cars, suppose now I have a moggie I should start to learn

Any help would be great, Paul

if you raise the tickover is it better?
Lumpy running at low revs can be may things (poorly set up carb etc..) but may be a sign of valve wear. Leaking valves have a bigger effect at low speed as there is more time for the gases to leak, and even with a badly burnt valve or seat an engine will seem fine at high revs.
Therefore if the basic checks don't reveal anything you should look to get a compression test done

It COULD be that it's running rich a bit (does it sound like it's 'hunting'?). When you pull the choke out a bit although you are making it EVEN MORE rich, you are also raising the tickover speed via the fast idle cam which will stop it stalling.

What colour is the inside of your exhaust and your spark plugs?

Hi, thanks for the replies.

The head had the valves done and a new head gasket fitted at a garage before I bought it so don’t think that could be the problem.

Spark plugs seem fine so is the exhaust. The only reason I pull the choke out a bit is to keep the revs up so it runs smoothly, if I don’t it runs erratically and not smooth.

Hope that helps a bit?

Hunting?

Thanks again, Paul

Paul,

If the mixture is too rich at tick over, the revs increase (more fuel = more power), but then dies away because there isn't more fuel/air mixture, andthe cycle repeats. Technically "hunting"...

The easiest checks are:

1) Air filter - when was it last changed? - is it filthy dirty? (choked air-filter = not enough air -> rich mixture)

2) Air filter - pipe from rocker to air filter - is it bunged up with oli/water mayonaise? Mine was nearly blocked after the winter - lots of shortish runs. Appears fairly normal with moggies.

3) unscrew the black plastic knob in the SU Carburetter - there should be oil inside (my book states SAE 20, others use 20W/50). That damps the piston in the carburetter to avoid rapid changes.

4) Check all plug leads and connections (sometimes the connectors on the plugs unscrew)

5) Check the idle mixture of the carburetter - typically with the Gunson device - this is a large nut under the carburetter, but doesn't normally change its setting without "help"

6) Check the points, etc., and the idle speed.

Let us know how it goes...

Colin