Man it really shouldn't be that bad if u use a heat gun. At least get the motor to around 170-200 degrees and it should fire up everytime. At least mines did

I too use the heat gun method. Heat it enough and it fire up the first time.
To break-in a engine. It should fire up first. Without a heat gun. It would be harder and longer. Pain in the a$$. But you will be rewarded later.
I didn't even need to change the conrod and wrist pin. It is the heat gun method which makes it easier to fire up helps safe the rod.
Mine had over 5 gallons now. And I haven't change one part.