lawn mower engine

[stonecreek]

A friend gave me a Sears self-propelled 6.0 HP lawn mower because he got tired of messing with it. It's not very old and the symptoms are:

When it's cold, it takes 3 or 4 pulls to start it. After it starts, it runs fine even until the tank runs out. If you turn it off after it runs for just a few minutes or much longer, then it will not start until the next day. I have another Sears that isn't self propelled, but the carbs were identical. I swapped carbs between the two and the symptoms are the same, that is, the trouble stayed with the self-propelled.

Any ideas?

thanks

[m Ransley]

Could be the ignition module or coil is going, when you turn off a motor it temporarily gets hotter probably triggering the module. Unless if it has points it could be the condenser , be sure it is clean and removing the shroud may temporarily help. Are fuel lines the same, routed away from heat and the carb has the right gasket to prevent vapor lock? Check for spark first when it wont start, if it has spark squirt fuel in the carb.

[Oscar_Lives]

Yeah, it probably isn't the carburetor.

Maybe it is the loose nut behind the handle...

[SJF]

Loss of compression? Burned exhaust valve, worn rings?