Hi all, I have an old Cushman Front Line 72" mower with a 2 cylinder diesel engine. I think the engine was made by Mitsubishi but I am not sure. Model number 898805. A few weeks ago it started smoking from the crank case vent tube and it had a noticeable drop in power. I checked for air in the injectors (bleed them) and that did not solve anything. Fuel filter is good, low pressure fuel pump it operating. I am kind of stumped and I understand that they no longer make engine parts for this model ??? I am afraid it might be piston blow by but it starts great and runs fine besides the loss of power. it only smokes when the engine starts to bog down and then I get black diesel smoke from the exhaust. Any idea's ??? Thank you for the help.