This part is a Crankcase. 
There is typical wear to the part as shown in the pictures. 
The item came off of a 1990 Honda Fourtrax 300. 
Item Manufacturer Part Number for the Left is 11200-HC4-000. 
Item Manufacturer Part Number for the Right is 11100-HC4-010.
If you have any questions, please feel free to contact us. 
If our price is not competitive, please contact us, or make an offer! 
-Blue Collar Sales and Service

This Honda 11341-HC4-000 COVER, L. CRANKCASE fits the following models and components:

Honda ATV 1990 TRX300 A - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1994 TRX300 A - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1996 TRX300 A - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1998 TRX300 A - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1997 TRX300 AN - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1997 TRX300 A - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1993 TRX300 A - FOURTRAX Left Crankcase Cover

Honda ATV 1992 TRX300 AN - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1989 TRX300 A - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1992 TRX300 A - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1991 TRX300 AN - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1988 TRX300 A - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1998 TRX300 AC - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1994 TRX300 AN - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1995 TRX300 A - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1993 TRX300 AN Left Crankcase Cover

Honda ATV 1995 TRX300 AN - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1996 TRX300 AN - FOURTRAX 300 Left Crankcase Cover

Honda ATV 1991 TRX300 A - FOURTRAX 300 Left Crankcase Cover