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MG Midget and Sprite Technical - A+ timing chain tensioner

Looking for the timing chain tensioner as fitted to a A+ engine .

I can find the metal mounting brkt (just)
Wearable tensioner pad , no problem
But the mounting pin that holds it all together I cannot find.

Any idea who might stock these parts?
R Mcknight not sure about.

but the regular A series dosnt have a tensioner

Prop and the Blackhole Midget

It should be the same as on the Mini but is NLS according to Moss(Europe) but it is part number 12G2629 which might allow you to find it somewhere else.

Rob aka MG Moneypit

Minispares keep it.

As above...

at 3.25 for the pin...or 15.25 for a kit including simplex chain,bracket & tensioner.

I run mine with tensioner & duplex. Marina block (not A+) but had been previously modified for the A+ tensioner + chain cover.

Dean Smith ('73 RWA)

Thanks lads , Now ordered . Many thanks Roy
R Mcknight

Well isnt that intresting....I have not seen that before

Obviously it dosnt use a 1275 timing chain cover,

it looks like a triumph 1500 timing chain cover and front engine plate that correct?

Prop and the Blackhole Midget


The A+ is more differant then I had always belived

Copied from mini spares....

Parts required to stop timing chain rattle on A plus engine with single row chain.Last chance to buy the plate and pin to hold the tensioner as they are

obsolete from Rover. Fitted to 998/1100cc from 1979 and 1275GT from 1974

Kit contents are,

3H2127 Timing chain

88G561 Oil seal

12G2625 Gasket

12G2621 Tensioner

12G2628 Plate to hold tensioner

12G2629 Pin to hold tensioner/plate
Prop and the Blackhole Midget

Prop, not sure what you're smoking.its a standard 1275 midget front plate with 3 extra holes to take a 1275 A+ timing chain cover.

The tensioner mounts in the 2 original timing chain cover bolt holes.

This is an assembled view. The cover just has a bulge compared to normal.
Dean Smith ('73 RWA)

I dont recall that jot out at the top left of the front engine plate where the timing cover fits

Prop and the Blackhole Midget

Hey Prop , is there a little voice in the back of your head saying you got to pull your engine and install one of these?
R Mcknight

Nope, nah-da, NOT, no way hosay...hahaha

Removing a timing cover is not a simple job

Prop and the Blackhole Midget

How much difference/improvement is there, compared to the original set up of not having a tensioner?
Lawrence Slater


On the mom and pop 1275 Id have to say minimal at think it would take xxx's of miles for chain and sprocket wear before the tensioner would ever come on line to begin functioning...when I replaced my chain and sprocket... it went in fairly tight

Those are my thoughts...not hayns

Prop and the Blackhole Midget

Yes, they tend to go in fairly tight especially when you first fit new parts, but after a few thousand miles they won't be. Fitting a tensioner will take out the slack from the gears and chain, and help keep timing scatter,(assuming you use an electonic module) to pretty much zero.

The chain tensioner works from day one - by damping down chain snatch it reduces wear and noise as well as providing steadier ignition timing.

Very early A series engines had a rubber ring in between the two rows of teeth on the crank sprocket to provide tensioning but once the rubber hardened the tensioning stopped!
Chris at Octarine Services

This thread was discussed between 20/01/2014 and 23/01/2014

MG Midget and Sprite Technical index

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