Engine No Diesel Power

I have a John Deere 430 Garden Tractor with a Yanmar 3-cylinder diesel engine. It has lost power and will stumble and stall under any load. It seems fuel related but I have replaced the fuel and air filters. My grass is getting long.

dwissinger said:

I have a John Deere 430 Garden Tractor with a Yanmar 3-cylinder diesel engine. It has lost power and will stumble and stall under any load. It seems fuel related but I have replaced the fuel and air filters. My grass is getting long.

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With diesel engines it could be multiple things that would give you a lack of power under load. You did the right thing by starting small with the air and fuel filters. That usually would clear up the problem. But since you still have the problem, I would check the fuel pump. If its pumping fuel, then check the injectors. A clogged injector(s) will play hell on power.