I left my bike in the garage for about 2 weeks and just haven’t had a chance to ride it during this cold season and today went to attempt to start it and this is what happened.
8 years WOW, that has to be a record!!! I never had a conventional battery last longer than 5 years even with a trickle charger. But usually on my Gixxer’s the stator or rectifier would go and kill the lead battery. I have lithium batteries in all my bikes now as well as a lithium trickle charger. The oldest one I have now is 4 years old, curious to see how long it last. They claim it last up to 10 years. They all weigh in around a pound or less!!!🏋️♀️🏋️♀️🏋️♀️If it's going to be sitting now, you should do some maintenance as well if you want it to start later.
You need to add the appropriate amount of fuel stabilizer and run it enough to circulate it through the entire fuel system and injectors. Fill the tank to the top as well.
Changing the oil/filter now is the best for storage.
Do all the other maintenance like adjusting/lubing the chain, cleaning the air filter, checking fluids, etc...etc... so you are ready to go later. Your battery may be toast. Only way to know for sure is to fully charge it and do a load test. I charge my battery about once a month or so at 1A, but don't have a maintainer. Original Yuasa battery lasted about 8 years, but most last half that depending on quality.
Do you have a volt meter? If not pick up an inexpensive one and we'll tell you how to check the battery.