I just want to make all aware of an EXPLOSION hazard your beloved 100 series lawn mowers.
I have a 119 hour 12 year old LA130 that I have kept in pristine condition. I change oil and filter every year, completly tune up every other year and replace belts every 3 years. Yes, I overly-maintain because I don't like to buy new.
At the end of last season, the gas tank began to leak. I figured "mower is 12 years old and tank is made of plastic, so it's probably cracked." I ordered a new tank (genuine parts) I set aside a few hours Saturday to change the tank, belts, oil, filters and plugs. The instructions seemed pretty simple, as I am an auto mechanic by trade. The first thing I noticed was capacity of tank is reduced by about half. No biggie, I proceed with install, following instructions to a T. However, the tank does fit nearly as snugly as the original tank. I double checked everything and still sort of loose. I added some foam rubber tape to the new upper support strap which seemed to help a bit. i am still only 90% happy with fitment of genuine parts.
Fast forward: after finishing maintenance, I inspect to see where the leak was. There were no cracks, no compromised seams, IT WAS LEAKING FROM WHERE TRANSAXLE FAN WORE THRU IT!!!!
Essentially, my 2 children and I were riding a BOMB!
I can't tell you when they redesigned the tank, but I can tell you what to look for. If you look between rear of green body panel and the black frame towards axle and can see the cooling fan, you're ok. If all you see is the white plastic of the gas tank, you should probably call your local John Deere dealer and have it looked at.