Diesel Engine Torque

i have diesel engine, kubota Z-482, maximum torque at 2400 to 2600 Rpm

i will use it at 1400 to 1500 Rpm, because i will only use for drive 2KW core-less PMG

did i must add the mass of flywheel engine with purpose to correct engine torque at low speed ....?

and if i try to add mass of the flywheel engine let say by 1.5 to 2 times from initial mass, what will happen ....? what is the bad impact .....?

regards

www.dieselenginemotor.com/kubota/supermini/page2.html