Thankyou guys, those who replied to my message "gummy residue" on Sep2005.

I've been spending some spare time since then, rebuilding that old abandoned_for_15_years bike,
following some of your advice, and now I got it running!

Thankyou guys!

Next job: rebuilding the gearbox. hehe, it's a yamaha!

Congrats on getting her running again!! Well done! Pics!