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MG Midget and Sprite Technical - Carb twiddling?
|My car (1275 RWA 74) bogs down when pulling away. Once it is on the move it seems to run ok and a little choke will see it behave better all be it with more revs. It has pancake air filters that have no filtering material other than course mesh and there is a bit of tappet noise that I intend to sort. I have not fiddled with twin carbs before and am reluctant to mess with something I might make worse. |
Would you change the filters?
Should I try adjusting the carbs or leave it to a mechanic. I am reasonably competent at most stuff.
Also, should the heater knob pull out and shut off the heat? It turns and switches the blower on, but is either stuck or is not meant to move (I thought it should) I'm cooking!
|I think I'm going to start all my postd with this -|
You could solve and prevent a lot of problems just by buying a owners Handbook at around £6 or £7, widely available as it tells you almost everything you'll want to know ands the full and proper service schedule - http://www9.mgcars.org.uk/cgi-bin/gen5?runprog=mgocregalia&a=&mode=search&cat=Handbooks
You can also get a glovebox sized (yes I know) Workshop Manual covering maintenance and repair to keep on the parcel shelf or boot to also show to clueless garages (not that you should use them) - http://www9.mgcars.org.uk/cgi-bin/gen5?runprog=mgocregalia&id=043161275748379&mode=search&cat=Workshop%20Manuals%2C%20CD%20Roms
The heater knob pulls out to close a flap on the metal tube just before the heater box so that say bus fumes don't go up the long black air pipe from the grille to heater box, this means you can't have the fan running - you're lucky your fan switch works, many don't and have to have a seperate switch, don't break it
Personally I would change the filters but they sound like the correct period aftermarket type
Once you've given the car a FULL and proper service (see ownes Handbook) and have eliminated all faulty parts and componets then take it in for a tune up and carb setting to a garage that knows whit it is doing
Or you could give it a FULL and proper service (see owners Hadbook) and then take it in for diagnostics at a garage that knows what it's doing
No use trying to tune up the 'engine' or carbs if everything else is out or faulty or needs servicing - horse before the cart
|Do the valve clearances first. 12 thou cold and mark with chalk or Tippex as you go. Then check the timing is correct with a strobe and the advance is working. There's plenty on this in the archives or read the workshop manual. Then top up the carb dashpots with engine oil and with the filter covers off push the pistons to the top of the bridge and let go. They should fall in unison and hit the bottom of the bridge with an audible clonk. Once you've done that you can start balancing the carbs and setting the mixture - but this needs to be done with a warm engine so do these preliminaries first and come back.|
|With regard to the heater problem, make sure that the flap in the heater is connected to the cable the right way round ie. push to open and pull to close. you first have to twist it to the left to be able to pull it as when it is twisted to the right it operates the motor and prevents it being pulled out. You can check the operation of the flap by removing the large trunking and watch the cable working inside the heater.|
BTW Iv'e got one with a working switch too.
|"Bogs down when pulling away" - Without adjusting anything else, try topping up the piston dampers on the top of the carbs.|
This thread was discussed on 05/06/2010
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.