Skip to main content
Collection, Preservation and Display of Old Lawn Mowers

Ransomes Marquis mk4 (or 4a?) - grass ejection?

Enter a word or two to search the forum section and click the Search Forum button.

My Marquis has never ejected the cut grass very cleanly. It only hits the grass box squarely if the clippings are quite short, and the revs rather high (probably 3mph walking pace). Otherwise, with longer grass, or lower revs, the clippings fall short of the box, and are "recycled" by the cutting cylinder.

I read the manual (posted by wristpin, thank you!)  for the earlier model with the Clinton engine, and it speaks of adjusting the "concave" (*). However, when I tried moving the concave mount points up and down, and no time did the concave move anywhere near the cylinder, certainly not anything like the 1/16" clearance the manual speaks of.

Can anyone advise?

   BugBear

(*) You can tell Ransomes made threshing engines...

Forums

wristpin Mon, 08/05/2017

If the cutting cylinder has been re-ground many times it will have lost diameter and have reduced ability to throw the grass. The brackets that secure the throw plate / concave may be reversed to move it closer to the cylinder and the concave itself can be "flattened" so that it is close to the blades in line with the cylinder shaft but not "curled" around at the top and restricting the trajectory of the throw.

A few images may shed some light on the matter.

gtc Wed, 10/05/2017

Link works for me, but some browsers and/or computers do have issues with Photobucket links. I have a PB account, but I don't have to be logged in to see those images.

I have found Imgur to be free of such issues.

That said, uploading photos to the Forum means that they avoid being subject to deletion/broken links later on.

 

 

bugbear Wed, 10/05/2017


 

bugbear Wed, 10/05/2017

 

hortimech Wed, 10/05/2017

That cylinder looks pretty low in the tooth to me and the gap between the concave and the chassis seems to bear this out. I think you need to find a new one.

wristpin Wed, 10/05/2017

Looks lower in one pic than another but overall looks low!  Can you give us an average depth of blade above the supporting webs?.

bugbear Thu, 11/05/2017

I shall attempt to measure cylinder height above the webs, and overall diameter.

If anyone has tips for measuring the latter, I'm all ears.

 BugBear

wristpin Thu, 11/05/2017

Not that easy with an installed cylinder but perhaps measure half and double it!?

bugbear Sat, 13/05/2017

(all in mm)

Web -> cylinder distance 6.00

Shaft diameter 19.12

Shaft -> cylinder distance 51.16

So radius = 19.12/2 + 51.16 = 60.74, diameter = 121.44, or 4.78"

What's a new one's full diameter (he asked, nervously)?

EDIT: the manual for the mk1, mk2 posted by wristpin give 5 1/8", so I'm 0.345" down on diameter, about 9mm, or 5mm off radius.

 BugBear

hortimech Sat, 13/05/2017

Hmm, I have known them get lower than that and still work, are these measurements all way across ? What I am trying to get at, could the cylinder be tapered ?

Could there be anything wrong with the bottom blade ? it should have a pronounced lip, but I have known people fitting a auto-certes bottom blade to a marquis in an attempt to get them to cut closer.

 

wristpin Sat, 13/05/2017

This is a 20" Marquis cylinder although, due to the rather rough welding, I suspect that it is a pattern part rather than a Ransomes original. Anyway, the diameter is 125mm

 

bugbear Mon, 15/05/2017

So I'm only 3.5mm down on diameter, roughly 2mm on radius. That can't be a problem, surely?

 BugBear

wristpin Mon, 15/05/2017

I would try "flattening" the throw plate a bit so that in line with the cylinder shaft it is 2mm or so away from the blades but is wide at the top so that the thrown grass travels in a higher arc to land further into the box. Also, maybe take a lighter cut.