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MG Car Repair/1969 MG Midget


QUESTION: I have a 1969 MG Midget that has been sitting for two years. When I start the car it idles fine, throttle response is fine, however, when I make any attempt to drive the car it all of sudden lacks power to accelerate and eventually will stall out.
I have adjusted the carbs so they are getting the same amount of air and fuel. The only other thing that I can think of to check is the timing from the cap and rotor. I am also thinking of new spark plugs and maybe some new fresh gas.
I did notice that when the clutch is depressed when the car is running that the idle drops a bit and also that last time I was working on it, it was very hard to start with the clutch depressed.
Is there anything else you can think of? I would really like to get it up and running.

ANSWER: Hi Nathan.  Certainly, stale gas can cause problems like this.  The two year old gas should be diluted with plenty of fresh gas.

Apart from the clutch problem , was the car running OK before you stopped using it?  

I would recommend that you give the car a full 12,000 mile service.  Clean and adjust the points.  Check and adjust the ignition timing.  Clean the points in the fuel pump.  A set of new spark plugs.  Fresh engine oil and a new filter.  Replace the air filters.  I would also check that there is oil in the carburettor dashpots.   And grease the front suspension.  And check the level of oil in the gearbox and rear axle.  And check brake fluid level...

Do not try to start the car with the clutch depressed.  Leave it in neutral until it is running smoothly.

One last thought.  There are two thin wires going to the ignition coil.  Make sure that the White wire with a Black stripe goes to the terminal marked either CB or - and the plain White wire goes to the terminal marked SW or + .

---------- FOLLOW-UP ----------

QUESTION: We have added about three gallons of fresh gas and some octane booster. I know when it was driven down to my mums house she said that it was little sluggish. Prior to her driving it, it had sat for a while as my father was disabled and unable to get in the car.
I am thinking that a good cleaning of all the major parts and new spark plugs would help it some.
It currently has the naturally aspirated carb stacks on the carbs, I do have the factory air cleaner set up.
When the car is in neutral, it runs fine, throttle response is good, you can run the tack up to about 4000rpms and then it wont go any further.
I will get  a set of plugs and clean all the points and go from there, I am thinking that because it has set for such a long time that it has some gunk in all the wrong places built up.
As I stated, once you put the car in gear and try to drive it on a flat surface and lacks any type of power for acceleration.
Thanks for your help, this gives me a path on how to proceed next.

ANSWER: Thank you for the additional information, Nathan.

I think the carbs may be gummed up.  Each one has a big dashpot on top, held in place by 2 screws.  There is a black plastic filler cap with a damper inside.  Do this on one carburettor at a time, so you cannot mix any components between the carbs:

Remove the damper.
Undo the two screws.
Lift the dashpot off the carb carefully.
Lift the piston off the carb (it sits inside the dashpot).  
Be careful not to bend the needle.  
If you turn it upside down, the piston will drain oil all over the place.

At this stage I would use a powerful cleaner such as Chillit Bang.
Clean the inside of the dashpot, which will probably have a sticky brown residue all over it.
Clean the outside of the piston, especially between the grooves.

Re-install the piston on the carb, making sure the needle goes into the jet hole it came out of.

Fill the damper tube with thin engine oil to within 1/2 an inch of full.

Re-fit the dashpot and damper.   

Do the same for the second carb, and give yourself a pat on the back.

I bet the car starts and runs much better after that.

---------- FOLLOW-UP ----------

QUESTION: I did manage to get it somewhat driveable, however, the gas peddle had to be nearly on the floor to keep it around 50mph, and now it wont stay running, it will start, run for a few seconds and the shut down, and I can restart it, run for a few seconds and it will shut down. I have cleaned the carbs, check the points, the float. It acts like it is getting enough gas to start but then does not get enough to stay running.

Hi Nathan

I think you are nearly there.
It could be the timing needs some adjustment.
Did you do everything on my long list?   

   o Clean and adjust the points.  
   o Check and adjust the ignition timing.  
   o Clean the points in the fuel pump.  
   o Fit a set of new spark plugs.

Regards, Barrie  

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Barrie Jones


MG Sports Cars from 1949 to 1980 - Including MGB, MGBGT V8, TF1500, TF, TD and modern Midgets. I also specialise in SU carburettors, Lucas wiring, suspension, steering & brakes.


I have owned my 1955 TF1500 since 1966. Technical specialist for the TD and TF with the MG Car Club T Register. Also owned 20 MGBs and currently own an MGBGT V8. Written 3 books on MGs and produced a DVD on how to strip and rebuild the TD/TF gearbox.

MG Car Club.

Barrie's Notes on the 1953-55 MG TF (author). /=====/ Barrie's Notes on the MGB (author). /=====/ Barrie's Notes on the MGB GT V8 (author). /=====/ The Essential Buyer's Guide to the MG TD, TF and TF1500. (author)

M Phil, C Eng, BSc (Eng).

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