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MG Midget and Sprite Technical - Do I have a dud starter motor
|Hi all. |
I rebuilt my midget a few years ago, including a full engine rebuild. I also fitted a rebuilt starter.
In the summer (when the oil is thin) the engine turns over and fires fairly quickly. However in the winter the engine only turns over very slowly and will not fire. If I jump it with a higher capacity battery hat I know is good it stil doesn't start. If I spray some ether into the carb it will eventually start and once warm it restarts fine.
To me it sounds as though the rebuilt starter is a dud. What should I do? Buy another or go for a gear reduction?
|Engine earth strap ???????|
Also...did you oil / grease the starter?? If you did...your a bad boy straight the the prinicpals office for your spanking
Id also have a pro test the battry ... it could be a little long in the tooth
|Jump lead from battery to somewhere near the starter motor was the test I used, to check the earth.|
But it turned out to be the starter motor anyway.
|Nick and Cherry Scoop|
|Replaced bushes on mine. Been great since. (needs big soldering iron).|
I presume that should read brushes not bushes.
|Tried the jump start with the earth lead attached to the engine.|
Would be annoyed if it was brushes given it was supposed to be recon but will look.
|Oops, yes Dave, brushes.|
Soldering iron was old Victorian heat on the gas ring. No sweat with that. Spot on.
Otherwise all I did was clean out dust, clean up the commutator? (contacts on the armature), general clean outside, check cog OK, check spring OK, and check main shaft not worn. Cheap. 1/2 a day.
Original brushes down to next to nothing causing little to no contact. Felt like poor battery /no power before fixing.
|Hi Tim. |
As Dave said brush replacement is cheap, straightforward and not difficult if you can solder. I used to use the big victorian iron but I lost it years ago. But while you have it apart it's good to use some contact cleaner or brake cleaner spray to wash out the gunge and carbon debris from the assembly. (But not the bearings).
I did brush replacement on a motor for a 70s mini not long ago (August or September I think) which is basically the same thing as a Spridget starter. I used a powerful (120W) mains powered iron that I bought online for about £15. It looks like a little pistol with a trigger switch.
In the old days we used to undercut the insulators between the segments of the commutator very carefully with a hacksaw blade or a Swiss file but I haven't bothered for a long time to do this. I don't think anyone else does either. Just clean up the commutator with fine wet and dry paper.
Prop is probably referring to not lubricating the exposed shaft of the starter. He is quite right. It must be scrupulously clean and corrosion free. Dirt, oil or grease on the shaft will not stop the starter working but it can stop the bendix returning cleanly to its rest position.
If you are really stuck I have a perfect spare starter up for grabs.
Finally; good luck.
I'll have a look when I am next under the midget.
This thread was discussed between 28/12/2016 and 29/12/2016
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.