Morris Minor Owners Club

Could anyone give me a clue as to what could be causing the engine on my 1968 saloon to stall when it gets hot after 10-15 minutes.
The engine is totally original 1098cc spec apart from electronic ignition (godsend) and a new standard coil which was fitted last year. The morris was running fine a couple of months ago when it was used daily (and the weather was good) but since, it starts up first time but has stalled on every runaround when the engine gets hot. I've checked the dashpot and topped it up, cleaned the carburettor - petrol getting through but still stalls, however the coil feels really hot when the engine has stalled. :roll

Mogs are known for fuel vaporisation on hot days!. You can usually tell if this is the problem because the fuel pump runs and runs with the ignition on but engine stopped. Does yours do this? If not it may be the pump itself.

you could try changing the theromstat. this may stop the engine getting hot.

Don`t mean to state the obvious part is the carb set up right mixture and tickover that sort of thing, what did you do when you cleaned the carb ?

Have you still got the old coil? It may be that the expansion of metal is causing a short / open circuit somewhere in the low tension circuit.

The only other time I've come accross this type of problem is when the jet is partially blocked. When warming up, the choke is out and petrol can get past. If the problem appears by itself (i.e. not just when you put the choke away) then this is quite unlickely to be the cause.

Can you keep the engine running by keeping the revs up, or once it stops, is it dead until it cools down?

Ben

Do you mean that the engine stalls WHEN YOU SLOW DOWN once
it has warmed up? If yes then it sounds as though you are
running too rich (BLACK smoke from the exhaust when you
rev up) and sooty plugs when you remove them. The mixture
control nut is in the middle of the carb at the bottom and turning
the nut UP one flat at a time will weaken the mixture. If adjusting
this nut makes the tickover speed increase(when hot) then a rich
mixture is indicated. Remember how many flats you move it so
that you can return to start point if no improvement. If the
symptoms are not as above then you probably have a heat related
breakdown in the coil/ electronic ignition as suggested. I assume
that your tickover is not set at very low revs.

Yup, I'd back up the mixture thing.

When Hebe was still quite a new member to the family her mixture was off and she stalled several times when she'd been running a while. On one particular occasion she stalled half way accross a very busy junction in Reading. The funny thing was there was a policecar just behind me who didn't even help us clear the junction!

If you look back in the threads there's a post somewhere on setting the mixture etc etc... I know, because I started it!

Good luck!

I'd go for the fuel vaporisation idea too. Try turning the air filter housing so its receiving air from the front of the car rather than the exhaust manifold.
Also, a few years ago, a Moggie specialist (I think it was Mr Grumpy's) sold a heat shield kit for the carb and fuel line for this very reason. Try giving them a ring to see if it's still available.

Shirley is it still happening now the weather is cooler ?

shirleyB wrote:Could anyone give me a clue as to what could be causing the engine on my 1968 saloon to stall when it gets hot after 10-15 minutes.
The engine is totally original 1098cc spec apart from electronic ignition (godsend) and a new standard coil which was fitted last year. The morris was running fine a couple of months ago when it was used daily (and the weather was good) but since, it starts up first time but has stalled on every runaround when the engine gets hot. I've checked the dashpot and topped it up, cleaned the carburettor - petrol getting through but still stalls, however the coil feels really hot when the engine has stalled.

Thanks for all the replies, it turns out it is the coil after all. I spoke to a mechanic friend the other day and he diagnosed the coil straight away as being on its way out. Apparently the magnetronic ignition I fitted gives out slightly higher ampage than the normal points setup, so a standard coil would be fine for 6 months or more but eventually will burn out due to the higher current generated from the electronic ignition. I don't know if anyone else has experienced this problem with electronic ignition and coils but I will be fitting an high performance coil which should correct the problem. [/quote]