Mountfield model Mirage lawnmower shuts down after about 5 mins, normal starting procedure, and after leaving mower for a cooling period of 4 or 5 mins mower will start normally and shuts down after another period of operation of 5 mins or so.This would appear to be an overheating problem, any ideas please?

George the Gardener, August 2008

many thanks for your advice ,Phil, pleasant?...breakdown of the plug was the answer, changed and all ok... thanking you again for your prompt attention George

George the Gardener, August 2008

Never had to replace a "coil" on a Briggs engine in 10 years of repairing! Very unlikely to be the coil.

pleasant, August 2008

No thermal cut out? Correct - unless the coil is suffering from high-temperature break down. This is not uncommon if the engine has previously overheated. 3 types of engone have been ftted to the Mirage over the years. New coils are available, as are 2nd hand ones - try ebay for Briggs 'Quantum' type coils is carb is on side of enggine, 'Classic' type if the carb is on the tank, or Tecumseh BVS if it's a Tecumseh engine.

phil_saunders@bigfoot.com

Phil Saunders, August 2008

If it's an overheating problem then cutting out and re-starting are not the symptoms- there is no thermal cut out device fitted.

Probably fuel starvation or plug breaking down. Change the plug- if problem is still there then run the engine without the fuel cap- the breather in the cap could be blocked and it's causing a vacuum in the system

pleasant, August 2008