A well-maintained motorcycle, just like a well-maintained car is a worthwhile investment. Not only will your motorcycle last longer if you maintain it but will also have a higher resale value. To this end, it is useful to have some tools on hand that you can use to do some repair work yourself. The first issue to take into account is if you need to use metric tools or non-metric tools for your bike. A good set of sockets and wrenches is recommended; for metric bikes, you should have sizes ranging from 8mm to 10mm, 12mm to 14mm, and then 17mm and 19mm. Harley Davidson motorbikes tend to not be metric and it would be an idea to look for specific Harley Davidson tool kits, of which there are many available.
These are wrenches which have two open ends, yet not as useful as a combination wrench. A combination wrench has one open end and one box end. There are pros and cons to the length of the tool. Having a long length provides more power and torque but may limit the use in a small tight space, so you need to take that into account. It also may lead you to over tighten and even strip the threads if you have a wrench that you can tighten too much. A very useful torque wrench to have is the snap on 3/8-inch torque wrench. Another very useful tool is a Motion Pro 6-in-1 allen key
A basic work stand may be useful to buy, since you may need to support the bike while working on it. This is especially important when checking chain tension or oil levels. A pit bull stand is a good investment so that you can lift the bike enough to remove the tires if you need to. You can remove the wheels and chain and sprockets if you have one of these stands.
It is a good idea to have on hand a kit to temporarily plug a puncture. A string-type tire plug works well but only on holes that are small, so holes that are about 3/16 inch in diameter. There are many specialty tools that you can purchase for motorbikes, including specialty wrenches and sockets and T handles. You can also buy specific tool kits but again you need to check exactly what your particular bike requires and if it is metric or non metric.
If you have a battery that needs to be maintained, then you may find having a funnel to be useful. The funnel will make filling the battery easier. A hydrometer can be used to test the battery. In addition, a multimeter can be used to check the electrical system of the bike. When looking for tools, bear in mind that going very cheap is not a good idea. Cheap tools will not last very long, so you will end probably end up spending more money in the long run if you try to be a cheapskate.