[vhgmcbuddy]

That makes more sense, so I suppose that the next step is to check that the impulse is actually tripping at TDC at cranking speed.

[vhgmcbuddy]

Great news Alastair!
Regarding your drive problem, have you checked to see if the ratchets and pawls are engaged between the hubs and wheels? For forward drive both ratchets need to be engaged (they’re the ones with springs on them). In addition if you permanently engage one of the pawls (the ones which are just on hinges) it will engage reverse to the selected wheel making the machine turn in one direction when reversing. It makes turning round at the end of the row easier.
Peter

[vhgmcbuddy]

Good news! My engineer friend has said he can repair the piston! I may have to wait a while. He will also resleeve the cylinder. My next concern is that when I put the machine into forward or reverse, it appears to have no drive to the wheels. I can see the forward and reverse clutches are ok and the Miller drives ok. I am going to commit myself to a full strip and inspection. I believe this will be worth it in the long run although it may get expensive.

[vhgmcbuddy]

Probably too late this time round but there is a great article here about how to test and overhaul diesel injectors here:
https://www.anglo-agriparts.com/diesel-tractor-injector-testing-overhaul

[vhgmcbuddy]

Just been going back through recent completed listing on E Bay Ransomes MG and found an RAF liveried MG2 sold around 21st November. The seller says that it was used on airfields for grass cutting , his father showed it towing a starter pack for aircraft. So maybe more than rumour.

[vhgmcbuddy]

The spring loaded impulse unit only engages at low revs holding the firing point at TDC, as soon as the engine starts and runs at 600rpm centrifugal force holds back the impulse latch so that it does not engage running the timing at 20deg, btdc.

[vhgmcbuddy]

The MG5 manual is quite specific, the impulse timing is set at TDC

So, where does that leave the timing once the impulse has tripped?

[vhgmcbuddy]

The MG5 manual is quite specific, the impulse timing is set at TDC.
Also I am using original specification spark plugs, properly gapped at 0.035″.
I have obtained a replacement coil and I will fit it tomorrow.

[vhgmcbuddy]

Mate of mine brought an MG6, we got it going & fitted a NGK plug. It ran fine till it packed up. He messed around for days with it till I went over. All it would do was bang & back fire.

In the end we fitted an old Champion D16 plug from an stationary engine & bingo she runs a treat!

That’s an interesting observation – my Dennis does not like NGK plugs. It will run on a new one but once stopped will not restart on it . It’s perfectly happy on old Lodge or KLG plugs.
I cant remember the exact detail but there has been previous correspondence on this forum about modern plug insulators being un-glazed? and getting contaminated by the products of the combustion of ethanol fuel – I think!

[vhgmcbuddy]

Have you tried a different spark plug?

Mate of mine brought an MG6, we got it going & fitted a NGK plug. It ran fine till it packed up. He messed around for days with it till I went over. All it would do was bang & back fire.

In the end we fitted an old Champion D16 plug from an stationary engine & bingo she runs a treat!

[vhgmcbuddy]

Iain, reading back over the posts, your “bang, bang,” might imply timing. Did you really mean you’d set it to spark at TDC? If so you need to set it to BTDC. Don’t know the exact setting for your application but I’ve attached a front photo of a SIMAR. The two round marks on the flywheel case are about the right distance apart.
Other than that I might suspect the impulse mechanism not working properly, as you are certainly getting a spark at low revs.
Peter

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[vhgmcbuddy]

I have received them. I just cannot thank you enough Charlie! I will post my progress! It is a beautiful machine and it totally complete. It was far to good to be scrap metal.

[vhgmcbuddy]

Hi Charlie, yes another drawing would be fantastic! The engineer is quite confident that he can either repair this piston or make me a new one. The drawings are invaluable as gaining spares is impossible! I really want to restore this machine to the same level as my Monrotiller but first I need to see how much time and expense is required to raise the piston. The cylinder will be easily repaired with a sleeve and I can have new rings made. Thanks once again, Alastair

[vhgmcbuddy]

I’ve no specific MG knowledge but the general principle for setting timing where there is an impulse starter is to turn the engine until the impulse trips and the turn it back to set the timing. Setting to TDC seems a bit wrong, is there not a BTDC figure?
On the subject of bench turning mags with a drill or even just flicking them over, the HT lead should always be connected to a properly gapped and earthed (to the mag base) plug. Not giving the spark somewhere to go can lead to internal tracking and a ruined mag.

[vhgmcbuddy]

I live to the north of Glasgow. Tucked in behind the Campsie hills, in a small village called Fintry.
Only 20 miles from the centre of Glasgow, but it’s another World!

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