Ransomes Marquis 18"- tuning

[vhgmcbuddy]

I’ve just managed to get my Grandfather’s old Marquis running. It is, however, very hard to control, it is either running very fast (and cutting beautifully) or stopped, it is very difficult to get it to run at a fair walking pace.
Is this likely to be an issue with the engine or the running gear? Should I strip down the clutch or lubricate the gears?
I am very new to dealing with vintage lawnmowers so any help would be gratefully received!
Jon

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[stuart]

I guess the carburation needs some attention.That particular engine should idle beautifully so strip and clean the carburettor and adjust the throttle stop screw (the one with the lock nut in the pic) to obtain a nice “tick-over” speed.It may also need the ignition system looking at too.

[wristpin]

As has been suggested, all that may be needed is a thorough clean of the carburettor.
However it should be noted that the BSA/Villiers Sloper engine fitted to the machine is “ungoverned”. That is to say,there is no automatic compensation for changes in load – its all down to a sensitive finger on the throttle lever.
In the interest of reliability it may be worth considering replacing the contact breaker points and condenser with a a solid state electronic module such as a Meco or Nova unit. Once fitted these remove the need for regular magneto maintenance and give a degree of automatic ignition timing not present with the standard system.
There is also just a possibility that at some time the centrifugal clutch shoes have been refitted incorrectly: this results in a snatchy take up of the drive rather that the correct smooth take up which allows a Marquis to be driven “on the throttle” and the landroll clutch reserved for emergencies and parking.

[hillsider]

While in the clutch checking the shoes also check that the clutch shoes move freely on their pivot pins. If these are not moving freely the drive may not take up cleanly and will only drive the machine at higher engine speeds.

[vhgmcbuddy]

Thank you all for your answers,I’ve got it idling well now, it starts like a dream and I’m learning to control it on the throttle (I think a new cable may be in order.) I do think that the clutch isn’t as free as it should be, so any advice on how to free up the clutch drum so I can free up the shoes which I don’t think are moving freely.

Thanks all for your help.
Jon

[wristpin]

If your machine has the telescoping shaft guard it may be easier to remove the engine but some access may be gained by sliding the drum away from the engine.
If you look at the shaft there is a circlip which limits how far from the engine the drum may be slid. Clean off any old paint etc from the shaft and open the circlip enough to slide it and the drum along the shaft. In the drum boss there’s a small grub screw, undo it a couple of turns and you should then be able to slide the drum away from the back plate and expose the shoes. Carefully lever them away from their pivots and when free you can unhook one spring and remove the shoes from around the shaft. Clean up the pivots and put just a smear of oil on them before refitting the shoes. The pivot ( anchored) end of the shoes should lead. If assembled with the free end leading the clutch will snatch.
Personally I would just unbolt the engine and pull it and the clutch back plate away from the drum but sometimes separating the shaft from the spigot bearing can be a bit of a fight.

Looks like the forum software is cropping the scan of the clutch but clicking on it seems to bring up the full page!

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[vhgmcbuddy]

The drum is stuck solid to the shaft, moving the engine may be the easier option. Sounds like I was working along the right lines (I’d already identified the circling and grub screw) so, maybe a couple of gallons of WD40 might help.

Thanks, I’ll persevere.
Jon

[wristpin]

The drum is stuck solid to the shaft, moving the engine may be the easier option. Sounds like I was working along the right lines (I’d already identified the circling and grub screw) so, maybe a couple of gallons of WD40 might help.

I don’t rate WD as a penetrating fluid. Plus Gas or even plain old diesel are far more effective. If you do end up removing the engine it can still fight a bit as either the top shaft has to pull out of the spigot bearing in the clutch back plate or the bearing itself has to pull out.
Once you’ve sorted the shoes spend time freeing the drum as having it slid back makes it easier to enter the shaft into the spigot bearing which, being self aligning, has a tendency to tip and frustrate the operation. Filing a slight chamfer on the end of the shaft and giving it a good polish up with emery cloth plus a drop of oil will help it to enter the bearing but you may still need to apply hand pressure to the starter housing while carefully tapping the top drive sprocket with a soft hammer to get the shaft fully into the spigot bearing.

[vhgmcbuddy]

Took the engine off, freed up the shoes and the clutch pins. It runs beautifully. I’ve also mastered driving it which was a challenge. I had no idea. That you are supposed to release the clutch then increase the throttle, that was a revelation.

My lawn looks fabulous now! Thank you so much for all your help. Now I have to decide how far I go with repainting the machine. At the moment I think I will do the petrol tank, the grass box and the side panel. Part of me wants to keep as much as original as possible.

Jon

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