Engine Block Issues *HELP*

[niteblade]

hi, my dad sent his bike in to the workshop recently because of a leaking head gasket.... hes run the bike fine for over 12 years without any major issues other than regular servicing... the carbs havenft even been taken out since day 1

he decides to do a top end rebuild since its about time he did a major service

- Replacement of tensioner
- Replacement of tensioner chain guide A
- Replacement of tensioner chain guide B
- Replacement of block gasket
- Replacement of head gasket
- Replacement of all 16 valve seals
- Service all 8 inlet valves
- Service all 8 exhaust valves
- Replacement of all 16 shims
- Balancing of all shims
- Lubricate/ adjust drive chain
- Check cam cover oring + 8 x head mountings

the mech calls him and tells him that his block has a potential leak and is rusty because the coolant is not running inside

however the bike has been running ok all this while without any overheating issues... should he trust what the mech says? the cost of the block is crazy....

[Jonesy7r]

What bike is this on?