Lookswise I'd restore it to original but if you want to get a few more beans out of the motor there are some things you can do. I made the following mods to my sons Kawasaki KFX50 quad (same motor as the ALT and the LT50 quad) and they really help. When it's all done and back together the only things that are visible and give away the mods are the aluminum silencer and throatier exhaust note.
1. Remove all restrictors. There's one for the carb where it bolts onto the little elbow shaped intake manifold and one in the cylinder where the exhaust bolts on.
2. Put a K & N air fillter and Outerwears on. You have to modify the plastic air box and a motor mount to accept it, but it can be done. Use filter
#RU-0200.
3. FMF makes a pipe/slicencer combo for that wakes it up a little. It doesn't have an expansion chamber, but it does help.
4. Rejet the carb. A must do if you make the air fliter and pipe swap. Replace the #55 main with a #75 and remove one of the stacked pilot jets.
5. Eliminate the oil injection system and run pre-mix with a good synthetic oil.
Current Ride (Purchased new in Oct. 84) - 1985 Honda ATC 250R w/ ESR 310cc big bore kit
Wife's Ride - 2009 Polaris RZR 800
Kid's Rides - 2009 Yamaha Raptor 700, 2008 Yamaha Raptor 250
Former Rides - 1975 Honda XR 75, 1979 Yamaha IT 175, 1978 Honda ATC 90, 1980 Honda ATC 110
got sand?