thank you for reply. wouldn't you think that if its the head gasket then i would be boiling coolant consistently? because since i topped it off with 50/50 mix, i haven't seen any bubbles.
the temps are better but not stable now. i will definitely replace the cap. I'm trying to reason what would happen if the head gasket was letting exhaust into coolant system.
Nope. That's not the way it works. In my case, the head gasket was only an issue at high RPMs when the combustion pressure was high enough to sneak a little air out. Then it was a cascading effect with the air pocket allowing the coolant to boil. I used a cooling system pressure tester and it held tight over a 24 hour period of time. I also used the gas detection liquid and saw no signs of exhaust gases in the coolant. The bike would heat up, fan kick on, and cool down like normal. All up until I'd ride it. Then it would overheat. All of the static checks passed. Even after removing the head gasket there was no obvious signs of damage. But after having replaced it, there's been no issues.