NPC Viper Slipping ideas????

[Lightspeed]

Has been all good after I gave it a good burning.

If the crank breaks the crank breaks. I will fix it and move on in life. People fit lighter and heavier flywheels to engines all the time. I don't see why, when balanced as part of the rotating assembly, it should add any great deal of stress to the engine.

Thats my opinion, and when my crank is in pieces I will search for the answer.

It's only the high horse power TD42 after market turbo engines with the viper flywheels that seem to be breaking cranks & quite a few have broken. It isn't the balancing it's the weight of them causing vibration over time which seems to be cracking them that's why a lot of guys have had a few Kgs taken of them to get them to standard or lower than factory.
I just mentioned it incase you end up taking your clutch out that's all.