[vhgmcbuddy]

This looks as if it could be a T series Sturmey Archer engine which would have been fitted with a Lucas manual advance/retard magneto however these were troublesome, very expensive to repair and dangerous if not used correctly. For safety and successful running I would fit the later MG2 magneto which has a centrifugal adv/retard and impulse starting aid. Neil Jarrett is the man to source a magneto. I used to own until recently number 137 which was number 36 off the production line from February 1936, do you know the serial number of this machine? If not on the model plate it may be on the front left leg of the engine mount frame or the underside of the gearbox cover.
These engines are very rare as most were replaced with the later TB engine after a number of accidents.

• This reply was modified 4 years, 2 months ago by .

[vhgmcbuddy]

From what I remember of Model aircraft fuel it would certainly have good penetrating / searching properties, even when past being suitable for its intended purpose. As far as proprietary dismantling potions go, Plus Gas has been my go to product for many years but some people favour a mix of automatic transmission fluid and acetone. For assemblies that need a good soak, I have a 25 litre topless drum of red diesel; ideal for seized Ransomes Marquis rear rollers which have never failed to yield after a week long soak – as yet !

[vhgmcbuddy]

Hi all just a quick update on the progress so far. I finally managed to get the calipers apart with a combination of heat a hammer and half a can of old model aircraft fuel. The fuel is a bit random but I found it in the shed it was a dark colour so no good for engines I cut the top off the 5ltr can and submerged the parts after they had been heated and left to go cold obviously. Don’t know if it made any real difference but after a few days of soaking the calipers came apart family easily. I will need new brake pads and will give the discs a skim on my lathe. It does make me smile when I look at how substantial the brakes are on these machine’s it looks like tank technology.
Best wishes William

[vhgmcbuddy]

Many thanks for this. I believe I have ruined a perfectly good set of plates!
However the problem was definitely in the clutch. You could hear a metallic gratingf noise `nd the drive pulley to the V belt would stop turning. I am guessing it was a combination of the birrs and the wear to the metal counter-plates that was causing it, and simply cleaning those up would have done the trick!
I have managed to find a set of used plates on ebay but they are in pretty poor condition. Probably worth a try though.
And yes i will keep my eye out for a donor machine!
Thanks all for all your input, much appreciated. I wish I had asked the question before starting the job!

[vhgmcbuddy]

So I carefully sanded out the lips so I had flat plates again and whilst at it had the clutch plates re-lined.

No experience of the the MT cutter drive but assuming correct assembly, the answer must lie in the re-lining. Presumably the firm entrusted with that operation were either given a specification to work to or purported to know the specification?
The starting point needs to be the correct specification of the friction plates; a ten thou thickness of friction material does seem a bit thin but spread over 11 plates may have been adequate
Hopefully Doe can help, even just one plate that can be measured may supply the answer. A complete set of plates will be “ gold dust” but I dread to guess the price.

[vhgmcbuddy]

I’ve just remeasured more accurately and there is still a nagging question…
Withe the 10 intermediate plates slipped on the shaft, there remains 12mmm of spline shaft exposed. The friction plate metal is 0.95mm each
.95×11=10.45
12-10.45 = 1.55mm
1.55/22 (for the 22 friction pads) =0.07mm and this would have to be the maximum thickness of each friction pad for all 21 parts to fit on the shaft. This cannot be correct surely? This is less than 3 thou!!
There is no way change the assembly , it’s pretty simple (see attached drawing). Part numbers 9, 14 and 15 all have to fit on p/n 8
Any thoughts?

• This reply was modified 4 years, 2 months ago by .

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[vhgmcbuddy]

That’s a great help, thank you. I noticed the burring of the ears and filed those clean, but will need to check the cage next time I’m up there. It sounds to me as if I have relined some perfectly serviceable clutch plates in error! i have searched high and low for replacement plates but they are just not available anywhere. Ransomes stopped making them years ago. There was probably no demand as it seems the clutch plates themselves didn’t wear out!
I’m now wondering if I can remove some friction material from the 22 sides to get them down to size? Probably a long job and difficult to keep them perfectly flat….

[vhgmcbuddy]

Trying again!

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[vhgmcbuddy]

There’s a sprocket on the side of this trusty tractor. Don’t know what it could have been used for. Any ideas?

John

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[vhgmcbuddy]

Might try that oil trick, tomorrow though. Thanks

[vhgmcbuddy]

Well I’ve taken the head off and had a look. Valves are working as they should. Timing seems spot on. The gasket is copper and is ok-ish few little spots of black carbon. Valves look OK. I suppose they might benefit from grinding. Don’t think any of that would account for zero compression though (correct me if I’m wrong). The only other thing I’m thinking is leaking past the piston rings. There’s no marks on the cylinder wall. It might have been “worked” on recently as the honing marks are clearly visible.

I suppose the only way I’m going to find out is to take the cylinder off.

John

[vhgmcbuddy]

Hi there,
Thanks for your quick reply,
Yes possibly although the valves seem to be operating well and there is plenty of compression.
George

[vhgmcbuddy]

George

Maybe your exhaust valve is stuck open. (if it has valves.)

[vhgmcbuddy]

Hi that’s brilliant thank you so much that makes sense now. It’s stupidly simple inside and now I know how much I can whack it.
Thanks again for your help and advice
Best wishes William

[vhgmcbuddy]

Hi it’s Will thanks for the advice on the brick cleaner I gave one assembly a good cook in a fire yesterday so fingers crossed I might be able to start a course of hammer treatment later. I just wanted to clarify does both of the round under parts come out (adjuster bolt side and lever side ) and do they both come out on the lever side. I can’t get my head around how they actually work I can’t find any parts diagram for them. I’m sure once apart it will be obvious.
Best wishes William

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