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Collection, Preservation and Display of Old Lawn Mowers

Ransome Marquis 18

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Hi

 

First post to here goes... I have a Ransomes Marquis 18 with a Vlilliers F12 sloper engine with an Amal 379 carb. The engine appears to be running too rich as there is a lot of black soot coming from the exhaust, to the point that when it runs past a fence it leaves a black stripe across it. As I said I would've thought its running rich but there appears to be no way of tuning it as there is only one notch for the clip on the float to locate. 

If anyone can help me with this that would be much appreciated. 

I am also on the look out for some new gaskets as I have a leak from behind the valve chest cover a point in the right direction would be great!

 

Thanks

 

josh

Forums

wristpin Tue, 12/05/2020

There is an adjustable needle on the throttle slide and the “ standard setting”  is the second notch down. Also wash out the air filter gauze  and check that the circular felt, circular gauze and felt washer are present and assembled in the correct order.

 Ignition issues can also mimic rich running issues . Try a new plug. A failing coil or condenser can also produce rich running conditions . 

JoshKemp Wed, 13/05/2020

So having taken the filter out and cleaned, the engine is running well. thank you for your help!

wristpin Wed, 13/05/2020

Oil leak from valve chest cover.  The covers often get distorted from over tightening of the centre nut. 

Lay a sheet of abrasive on a flat surface ( off cut of plate glass from a commercial glazier does well) , lubricate well with kerosene or similar and rub the cover over it. That will soon show up the highs and lows and with patience will true it up. Use a new gasket with a smear of heavy grease or Vaseline on both faces and don’t over tighten. 

JoshKemp Thu, 14/05/2020

so the valve cover was slightly distorted and now flat, issue i now have is finding a gasket for it. Do you think a generic piece of gasket material cut to size would suffice? 

wristpin Thu, 14/05/2020

The exhaust manifold gasket will need to be cut from "heat proof" gasket material the inlet should be OK from normal material as used for the valve chest. 

You may save yourself a lot of hassle by seeing whether Jon Cruse of The Hailsham Mower Centre will sell you a gasket set. 

JoshKemp Tue, 19/05/2020

All done! New gaskets for the valve cover exhaust and carb inlet, fresh oil, cleaned air filter and it now runs like a dream! Thanks for your help, although I'm sure I'll be back on soon enough..!