Small Engines (Lawn Mowers, etc.): mower smoking, poor engine performance, diaphragm type

Question
The mower is a Scotts 1642 and it starts and runs good for a short time then starts to smoke black and running rough can disengage the mower deck and idle it down the increase the speed and it smooths out until you engage the mower deck then it runs rough again and stalls.

Answer
john
Sounds like you need to rebuild your carburetor. Post the engine brand and all of the model numbers ect. Based on the problem description, the engine isn't getting enough fuel after the choke opens. Very possible the card is in need of an internal cleaning and new parts installed.

Check for a restricted fuel supply. This can range from fuel flow from the tank, through any inline filter, low fuel level in carbs with fuel bowls or a restricted carb of either bowl or diaphragm type. Try using fresh fuel to flush out any stale fuel while checking fuel flow from the tank.

Also check the muffler for good exhaust flow. A damaged, overly rusted or excessively carboned up muffler may have internal damage causing an exhaust restriction.

Exhaust restrictions can cause several problems. Overall poor engine performance, excessive engine heat, failure to accelerate properly, hard starting, rough running and many more.