Morris Minor Owners Club

Gladys, 948 cc 1962 is now nearing the end of overhaul.

New Dissy, Starter, Manifold, Head Gasket and Cylinder Head.
Dave Clifton rebuilt the carb for me, so the piston, needle will be set dead right
also he checked the Dissy and Starter and fine tuned them.
The problem is, I can't get her to start.

Gladys will fire if a teaspoon of petrol is dropped down each spark plug hole, but once that petrol is burned she stops.

Dissy, plugs, battery, timing all OK.
I've had the fuel pump (new 2 years ago) off and cleaned the filter (no dirt in it at all) and it pumps the petrol through fine enough (jam test).

Compression on each cylinder is 8 bar approx 116 PSI.

I've fitted the new throttle cable , no problems, but suspect that the choke cable I fitted is a likely suspect for the inability to start and I may not have got it quite right.

Question 1.
What IS the correct procedure for fitting the choke, e.g. how does one decide where to place and tighten the pinch bolt?

Question 2
It's a new choke cable, but the original type of pull out and twist to lock, rather than sticky type.
The cable itself is within an outer chrome type braided cable.
The inner part one threads through a hole down to the pinch bolt-BUT does the chrome, braided outer part go firmly into the round cable keep so tight that it doesn't move, OR, should both the inner and outer parts of the cable move freely through the cable keep?

Question 3
I've heard that the choke has to be fine tuned to a "cam" using a screw found on the carb, and in conjunction with the Idle screw, how is this done??

Best wishes
Sloopy

Q3 - the 'cam' in question pulls on a fraction of throttle with the last part of the choke movement (play with it to see)

Q2 - the outer braid stops in the bigger hole (but is free to move in the direction opposite to pulling the choke on).

Q1 - choke knob in 'off' position, outer braid seated in the bigger 'hole', feed inner through & pinch up with only a very little slack.

You could temporarily jam or hold the choke open to try it.

If you have fuel in the float chamber & it will fire with fuel in the bores, then there must be a blockage in the bottom of the float chamber, the little pipe linking to the jet, or the jet is wound up too far to allow much fuel out. Try a few squirts of fuel in the carb intake - should have the same effect as in the bores.

If there is no fuel in the float chamber then it's the pump, tank (empty?), or lines.

Phil.

The compressions are desperately low - however - that's no affecting the starting - it will however affect how it will run. Obviously ignition is fine - so the problem is fuel related. Exactly what was done to the carb? Does the piston rise and fall easily? Is there any fuel in the float bowl? Pour fuel down the carb throat (not spark plug holes) and crank it. The choke mech is thoroughly described in the Workshop Manual.

Check for fuel in the float chamber before trying to start the car.
Remove air filter and lift the carb piston, it should drop smoothly onto the bridge.
The end of the outer choke cable should fit in the cable stop and there should be a little slack on the inner cable when it is clamped to the end of the choke lever with the pinch bolt.
When the engine is warm, unscrew the fast idle screw so that it is clear of the cam then adjust the tickover screw to give a smooth idle speed. Screw the fast idle screw back so that it is just touching the cam, just as the revs start to rise. This should be the correct set up to keep the engine running when the choke is pulled out

As you have confirmed fuel at the pipe to the carb. then if the float chamber is not full obviously the needle valve is stuck closed.

If the float chamber is full check the jet tube is not blocked where it fits to base of the float chamber.

Hello and many thanks for the advice.

Fuel is getting to the float chamber right enough so as you say it must be ftrom the small pipe onwards.

I guess the compression readings , 8 bar, are low because she hasn't run in a long while, almost 12 months.

When fitting the manifold, the recommended torque is 15, however the nuts are brass and so someone advised me to do 13 torque, apparently it has been known that 15 will crack the manifold, sometimes?

I will be back on Gladys tomorrow.

Once again, I am both amazed and grateful at the pool of knowledge that the MMOC has, I have found it indispensable. Thank you all.
John

bmcecosse wrote:The compressions are desperately low

That's assuming the OP measured them correctly: given that he's not really clear in his own mind what's supposed to happen when you pull out the choke, might he have measured them wrongly, for example with the throttle not fully open?

My guess is that he's trying to start it with no choke - and the carburettor rebuilder may even have expected the owner to do the basic mixture setting, too, and have left the jet screwed right up.

Kevin

Compression readings obtained whilst turning the engine over and throttle cable open to the maximum.
The chap who refurbished carb is Dave Clifton, a local Moggie expert, who set the carb to precise measurements, e.g. fuel richness nut to the precise number of recommended "flats", Float setting to precise azimuth jet centred perfectly.

The plugs should all be removed when doing the comp check - but don't worry at the moment - first get it started! The good news is that all the starting efforts will be getting oil flowing round the engine - which should always be done when raising an engine from slumbers. Petrol down the carb throat and crank it - should start.

Setting the carb mixture to the recommended number of flats (12) is only the starting point, when the engine if up to running temperature the carb has to be fine tuned to suit your engine, which may be a flat or two either way

sloopjohnrb wrote:Compression readings obtained whilst turning the engine over and throttle cable open to the maximum.

Sounds good - assuming you mean turning it over with the starter motor, rather than by hand. Did you observe that the throttle itself was fully open, or just foot to the floor - which may not be the same thing if the cable's not adjusted well? Anyway - that won't affect whether it starts.

Have you confirmed that the jet really does move down fully when you pull the choke out? And that the jet really is still centred (dashpot damper off, lift the piston with your finger, release, listen for the clunk)?

Kevin

Hi
Yes I cranked her on the starter motor using nhe button in the engine bay, and pulled the throttle cable by hand
fully open. The damper/piston lifys when pressing the spring onn the carb and makes the clunk noise when released and it drops down again.
That said, I'm going to have a good look at the carby tomorrow-without undoing any of Dave's work.
I am almost totally convinced it's the choke cable not engaging the choke propertly.

Thanks again