I always replace the plastic tank with those aluminum ones from comet. The sight glass is tygon fuel tubing and doesn’t leak just leave it a little long if you replace it because they shrink up a tiny bit. Put the mounting bolts up from the bottom and double nut so you don’t crush the rubber grommets and you’ll have a nice shock mounted tank. I also get one of those fuel nipples with a flange and put it in the cap then a small fuel filter on top keeps fuel from splashing. You’ll need a long neck funnel to fill the tank on certain ones if the steering shaft is in the way.
Hope that helps,
FAA certified jet engine and aircraft technician,
Nicholson Speedway class champion 2001,
Yamaha KT100 Service Center,
41 years karting experience