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MG Midget and Sprite Technical - MG Midget 1500 no power

Hi All

I have scoured the internet and i am really struggling to get hold of MG midget 1500 info.

So I have a 79 MG Midget 1500 which was running like a bag of spanners when i got it, so i did the normal service, points, plugs, air filter etc. and now it is idling ok (it has just passed an MOT) but on the road test it will not get above 30mph (the MOT station is in the village so i had no reason to go above it to take it there).

Whilst driving i have it in 4th gear and the engine revs climb when i press the accelerator pedal and the engine screams but now power. My initial thought is the clutch is losing friction but i am no expert. So i need help:

1: Any ideas why i have no power, could it be the clutch?

2: Dose anyone know any web sites where i can find the engine settings, Plug gap, points, Dwell angle etc.

Any help or info would be great thanks

Rob
R Johnson

It sounds like a slipping clutch to me. This is usually caused by oil leakage from the rear seals. Do you get any juddering from the clutch?

As for reference materials, you can pick up the Haynes manual for the Midget and it's a big help.

-:G:-
Gryf Ketcherside

Sorry forgot to say i have ordered a manual 4-5 days delivery i have tried everywhere no one stocks them..
R Johnson

Rob,
If the engine is revving freely but your road speed doesn't go correspondingly higher, then you do indeed have a slipping clutch.

The classic test is to find a hill, drive up it at a steady speed in 3rd gear and then rapidly depress and release the clutch pedal whilst still holding steady on the accelerator. The revs should increase as you press the clutch, but snap smartly down again as you take your foot off the pedal. If they don't then the clutch is worn and needs replacing.

Haynes manuals are plentiful and cheap on e-bay

Guy
Guy Weller

Rob,
If the engine is revving freely but your road speed doesn't go correspondingly higher, then you do indeed have a slipping clutch.

The classic test is to find a hill, drive up it at a steady speed in 3rd gear and then rapidly depress and release the clutch pedal whilst still holding steady on the accelerator. The revs should increase as you press the clutch, but snap smartly down again as you take your foot off the pedal. If they don't then the clutch is worn and needs replacing.

Guy
Guy Weller

I ran it up a hill on the test drive and it was in 4th but it slowly lost speed (lots of people behind me getting anoyed)

How easy is it to change the clutch on it?
R Johnson

Just driving up a hill doesn't tell you much - except in your case that you needed to change down a gear! Third, or second gear and a rapid dip of the clutch would be much more testing.

Clutch change means taking the engine out. It isn't difficult with the right equipment but it all depends on your level of experience. A garage would charge a full day's labour although it can be done in a lot less time than that.

Guy
Guy Weller

Where in Kent are you?

Haynes does have all the information you're looking for, but, it's a bit "bitty" and be ready to have to find the bit in the chapter that tells you how to do something - and then be refered to the start of the chapter - to then be mislead by the advertising space .... but hey - when you get the idea...!!!

One good website though is: http://www.totallytriumph.net/spitfire/engine_building.shtml - obviously, you have to make some adjustments in your mind, but, it lays out which parts of the engine SHOULD be doing what - and how you can get them sorted/improve them.
rachmacb

Hi Rachmacb

I am in a village near Tunbridge wells just off the A21
R Johnson

Ah - you need to get up hills then!!!

I know a great place a bit further up who isn't expensive, if you'd needed to take it to a garage, but it's up near Bromley sort of area :(

The only other thing I'd say is, yes, it's probably the clutch, but, once you've got that sorted, have a compression test done - and see what's going on.
rachmacb

Ok so here is an update, i have removed the engine today and the clutch apears in really good condition, any ideas where to go next?
R Johnson

Do a compression test - and check the tappet spacing
rachmacb

Hmmm . . . . "clutch appears in really good condition."

If your problem is caused by a slipping clutch, the diaphragm spring in the clutch cover could be weak. This wouldn't be obvious from a visible inspection.

You need to eliminate it as a possiblity of your problem.

You have two options:
(a) Find a local 'friendly' clutch remanufacturing workshop who could do a pressure test on your clutch cover;
(b) Buy a new, replacement clutch cover from a reputable source.

Depending on how much (a) is going to charge you, option (b) may be the cheaper route!

(I am assuming that your driven plate is in good nick, ie not contaminated etc).

Andy Hock

Rob,
The reason for identifying it as a slipping clutch was the information you provided:
" in 4th gear the engine revs climb when I press the accelerator pedal and the engine screams but no power."

This is classic for a worn clutch. As Andy says, it isn't necessarily obvious just from looking at the clutch mechanism that it is worn. It may look clean and shiny but if the pressure plate springs are tired or the driven plate is worn thin then it will slip. Having removed the engine you should remove the clutch pressure plate and check the surface of this and of the flywheel for cracks or heat discolouration. Check the linings on the driven plate for wear. There should be plenty of "meat" above the rivet heads - I think a new plate is about 8mm thick so measure to see how worn yours is.

Having got this far you have done all the work in getting the engine out and I would be inclined to buy and fit a new three-part clutch kit anyway.

The only other possibility that I can think of is that it is a gearbox fault. Especially if your "revving but no power" applied to 4th gear only and it didn't do this in other gears, but this wasn't clear from your first message. With the gearbox out, try selecting each gear in turn and check that when in gear both the input shaft and output shaft do rotate firmly together with no slipping.

Guy
Guy Weller

This thread was discussed between 01/07/2010 and 05/07/2010

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