Qualcast 35s engine won’t cut out
I have a Qualcast 35s (F016305542) with a Tecumseh AQ148 engine & carburettor. Which is a lovely mower but I have two issues with it. I’m not very mechanically minded but I have been able to sort out most issues but engines & electrics are a bit out of my depth, whichI hope I can solve with your guidance?
Firstly, the mower will only run smoothly if the choke is on! In the past, once the choke was turned off the mower would cough & splutter, then cut out. I have on several occasions I have taken the carburettor apart, cleaned with an ultrasonic bath but the problem still persists.
Secondly, the throttle control on the back of the mower seems to be at fault or it could be something else! The mower used to shut down once the throttle lever was turned to off but now the engine keeps on running, even with the throttle being off & the choke turned off as in the first issue, the engine still coughs & splutters until I remove the spark plug lead.
Any help would be much appreciated.
Forums
Thank you Wristpin. I’ve…
Thank you Wristpin. I’ve resolved the issue with the engine not cutting out. Now to resolve the carb issue!
The coughing and spluttering…
The coughing and spluttering needing choke , suggests that a more thorough clean is needed . As useful as u/s cleaning is , it’s not the be all and end all. A strip and a bit more probing may be required. If you find a schematic of the carb showing the fuel passages for starting and normal running will give a clue to where the problem may lie.
Stopping is a function of the coil being shorted out by a wire from the ignition unit to the carburettor / governor linkage where, when the control is moved past slow the linkage moves in contact with a terminal on that wire which will Earth out the ignition to stop the engine.