Ransomes MG2 looking for help to start

[vhgmcbuddy]

Hi All

I bought a couple of Ransomes MG2’s a few years ago, one in running order just, one in poor condition that came along in the deal. I did all the normal servicing, used the better one in forest a couple of times, then while ticking over it stopped, never to start again….yet

I took it to my shed, stripped clutch which was dragging, thanks Neil for tool loan, reassembled, but now can not get it started. All looks good, valve timing, ignition timing, carb clean, air flow ok, new plug and good spark, but even with fuel dropped into chamber, it will not start……I am out of ideas and looking for some experienced help.

Ideally I can bring the MG2 to anyone who can offer some help, you can not put old head on younger shoulder, and I really am out of ideas. If anyone can offer me an hour to see what I am obviously missing I would be extremely grateful, as I have next winters wood needing collecting, and I am getting too old to man haul it now…..

Thanks in advance, all advice welcome…..

Graeme Lewis

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[expeatfarmer]

Hi Graeme
Sounds like it may be a fuel issue take out the jets and blow them through with an air line.
In the past I have had similar issues and now as a matter of course if I want to start a particular tractor I go through all the key items remove and clean carb and jets, change petrol to fresh new. remove magneto and clean and reset points, check valve clearance, new spark plug. Then go for it.

For a first shot I would drain out old petrol from tank, clean carb and then try again.
Good luck.

[stuart]

OK so you have fuel,and the spark at the plug is good (and at the correct time / advance) then you must have a compression related problem.Check valves,valve clearences,worn piston and cylinder bore,leaking head gasket etc etc.
Drop some fuel down the spark plug hole and fit a new spark plug.If the compression is good then the engine should at least fire a few times and if the carburettor is good and the jets are clean etc etc then it should keep running:):)

[vhgmcbuddy]

Could be the condenser, on my mg5 and 6 they both appeared to have an excellent spark however under compression it was weak, if you don’t have a neon spark tester then try another spark plug in the lead then ontop of the fitted plug it will be harder to see but will give you an idea if your spark is failing under compression (plug must not be a resistor type)

[expeatfarmer]

Try using a color tune, you
will see spark under compression and quality of mixture.

[vhgmcbuddy]

Hi

Thanks for the advice, I will follow it in a logical all fashion and see what comes.

What is a color tune?

Cheers

[ransomes256]

Graeme,
Colour Tune is a special spark plug with a viewing window that allows you to view the combustion in the cylinder. I have never used it on this type of engine but can allow you to adjust mixture and view the spark under compression. If you follow the idea from Rhys you will obtain a similar result. If you think the engine lost compression it may be due to bore washing (too much petrol at idle removing the oil from the cylinder wall) Try spraying a little oil in the plug hole and turning the engine over without the plug to re oil the bore.
Neil

[vhgmcbuddy]

Ransome MG 2 still will not start, ALL ADVICE WELCOME work done today….

FUEL
Fuel system cleaned, jets clear, air filter clear

ELECTRICS
New points and condenser fitted, gap set
Cleaned Magnito cap in case of tracking
Magnitogorsk and coil tabs cleaned and set to touch
Replaced HT lead
Known working spark plug cap from motorbike
New spark plug and gap set

MECHANICALS
Valve clearance set
Valve timing to TDC ok
Valve seats looked ok
Head and copper gasket looked ok
Compression test was 4 bar dray and 4 bar with oil in bore, proving piton rings are holding pressure, not sure what compression value should be?

BAD BITS
Bent exhaust lower push rod, 0.006 to 0.008 variation on 360 rotation
Don’t know what compression value should be

STATUS
Now got regular spark, but yellow purple at plug….weak? Or normal?
Points still sparking slightly, purple blue even with new condenser

Any advice ?

[andyfrost]

How new was your “new” condenser , there are some sharks around selling 50 year old ones as new stock.
First and foremost in my book on any problem is to have the ignition system PROPERLY TESTED , get it tested/repaired , try it , and report back to us.

Andy.

[expeatfarmer]

Colortune is a very useful piece of kit ,it is literally a glass topped spark plug that lets you see into the head at the time of firing. It enables you to adjust the slow running mixture to achieve slow and smooth tick over ( shows up blue flame ) but also lets you see the colour and quality of the spark under compression. made by Gunson.
You said you had two MG2 ,I would be tempted to try swapping the magnetos, it may be that the magneto coil is failing, alternatively have your coil tested.
I have had similar problems with an MG2 that was to my mind set up perfectly and found that the position of the throttle lever at starting can be critical, it should be open about 1/4 throttle on the butterfly but you may need to inch it either way to get it to fire. On occasions I have also had to fit three different spark plugs ( new ones ).

[vhgmcbuddy]

Hi the Mag on the other MG2 is in poor condition, parts missing, so I have ordered a replacement Mag. Will come back once I have new Mag fitted. With new Mag and new fuel I am hopeful she will run.

[vhgmcbuddy]

The condenser is new new one from Neil, so think its a good one.

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