bertsmobile1
Lawn Royalty
- Joined
- Nov 29, 2014
- Threads
- 64
- Messages
- 24,705
So going back to basics
pop a can of carb cleaner in your mower and install a pair of in line red spark testers on the plugs
Then go mow
The instant it stops look at the spark testers .
If they are flashing red but the engine is cranking but not running then the ignition system is fine & the fuel system is suspect
Give the carb a shot of carb cleaner & crank the engine if it fires right up and you can keep it running for a minute or so by repeated short shots of carb cleaner then that confirms a fuel problem.
If it does not fire or won't stay running then you have a valve problem, most likely a badly worn cam lobe.
I have a one gallon tank of a Tecumseh walk behind that I use as a substitute fuel supply ( cause it has an inbuilt tap ) that I slip directly onto the carb.
Problem persists then the problem is in the carb.
Problem goes away then the problem is in the fuel supply
Not going to fix the problem but at least you will then know where to spend time looking.
If the carb is not a problem then I move the external tank connection further back.
If I get to the last element and the problem is still there then I know the tank is the culprit.
Beauty of working this way is you are doing your diagnosis while you are mowing so the grass is not reaching sky ward while you are beating your head against the wall .
Also you don't end up spending a fortune on replacing perfectly good parts.
Most people have an old push mower, tiller or something with a 1/4" fuel take off kicking around their sheds.
If not every mower repair shop ( not glass front sales rooms ) will have boxes full of old tanks that we all keep but never seem to use.
pop a can of carb cleaner in your mower and install a pair of in line red spark testers on the plugs
Then go mow
The instant it stops look at the spark testers .
If they are flashing red but the engine is cranking but not running then the ignition system is fine & the fuel system is suspect
Give the carb a shot of carb cleaner & crank the engine if it fires right up and you can keep it running for a minute or so by repeated short shots of carb cleaner then that confirms a fuel problem.
If it does not fire or won't stay running then you have a valve problem, most likely a badly worn cam lobe.
I have a one gallon tank of a Tecumseh walk behind that I use as a substitute fuel supply ( cause it has an inbuilt tap ) that I slip directly onto the carb.
Problem persists then the problem is in the carb.
Problem goes away then the problem is in the fuel supply
Not going to fix the problem but at least you will then know where to spend time looking.
If the carb is not a problem then I move the external tank connection further back.
If I get to the last element and the problem is still there then I know the tank is the culprit.
Beauty of working this way is you are doing your diagnosis while you are mowing so the grass is not reaching sky ward while you are beating your head against the wall .
Also you don't end up spending a fortune on replacing perfectly good parts.
Most people have an old push mower, tiller or something with a 1/4" fuel take off kicking around their sheds.
If not every mower repair shop ( not glass front sales rooms ) will have boxes full of old tanks that we all keep but never seem to use.
Last edited: