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Here I have a Briggs 128T02-0118-B1 on a John Deere a guy brougth me a month ago with a starting problem, the mower is only 2 years old. I got it started by spraying a little starter fluid in the carb and would run on it and start so I basically removed the carb and put in a needle and set and cleaned up the carb and put it back on. It would then start and run for a couple second then on the next pull it would start again wallop down and then back up to operation rpms and steady up. At this point he was happy with it. He used it 2 times and now were back to square one and will only start again with starter fluid sprayed in the carb ? I did a basic compression test and it was only 30. Here i have removed the head to see what we have. The black ridge of carbon on the cylinder wall? What doe's this tell maybe about the problem? Any help would be great! Odviously the engine is not getting proper fuel but also low compression ?//
:dunno:
 

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Welcome to the MLF, glad you stopped by. Carbon tends to build up after time in these engines and its not uncommon to have to remove the head to de-carbonize the combustion chamber. Clean the piston off and clean the valves and seats. An exhaust valve leak can cause an engine to appear to have little or no fuel for cold starting. When the piston moves toward the crankshaft, maverick air can enter the combustion chamber through the exhaust valve. The maverick air takes the place of the air-fuel mixture drawn through the carburetor. Without the proper air-fuel mixture, the engine has an insufficient amount of fuel vapor and does not start.
With a leaking exhaust valve, an engine with less than optimal compression can sometimes be started by priming the combustion chamber. Less fuel is required to keep an engine operating than is required for initial cold starting. The engine may operate acceptably when warm, but the leaking exhaust valve still affects engine operation.
 
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