Originally Posted by
1995 Monster T
You didn't break engine properly. You should have broken engine in at idle for 6-8 tanks then slowly drove truck as instructed only adjusting high only first then the low. last if needed. Use a new plug OS #8 and fuel with 14-18 oil lube for long engine life. and try again.
There are 1001 way to break in and all work. Yes, starting with idle is always good but for sure no must. Please, stop scaring people doing it wrong.
I would take of the heat and look into the combustion chamber and on top of the piston if some brown colour is showing. After that less it should not be much but it must be there. Next question is with the rebuild if you did put back all the headshims.