Yamaha DT501988 Owner's Manual page 11

3. Never attach any large or heavy items to the handlebars, front forks, or front
fender. These items, including such cargo as sleeping bags, duffle bags, or
tents, can create unstable handling or slow steering response.
ACCESSORIES
Genuine Yamaha accessories have been specifically designed for use on this
motorcycle. Since Yamaha cannot test all other accessories which may be
available, you must personally be responsible for the proper selection, instal-
lation and use of non-Yamaha accessories. You should use extreme caution when
selecting and installing any accessories.
Keep in mind these guidelines for mounting accessories in addition to those
provided under "LOADING''.
1. Never install accessories or carry cargo that would impair the performance
of your motorcycle. Carefully inspect the accessory before using it to make
sure it does not in any way reduce ground clearance or cornering clearance,
limit suspension travel, steering travel or control operation, or obscure lights
or reflectors.