Les, you know what Im going to say (no.. not seafoam).
Its not a tool unique to motorcycles, but motorcycles are often the first time a person with mechanical experience starts working on a machine where most of the steel bolts and threads are screwed into aluminum.
Its important to tighten up steel-into-aluminum bolts and fasteners correctly, and the only way to do that is with a torque wrench.
Here is the reason: when you tighten a steel bolt into a steel case or frame by hand, it will spin freely all the way in, then get snug, then get tight, and unless you are a gorilla you can crank on it hard and it wont strip out the threads in the case.
Aluminum is not like that, it will start getting snug, and then tight, and then you will be turning the wrench and its not getting any tighter, because you are pulling the threads out of the case, and now you have damaged the case and it will take hours to repair, and maybe hundreds of dollars. The hands on experience you have from turning bolts into a steel case WILL strip out the threads into an aluminum case.
Its easy to find the yamaha factory service manual for vstar bike online as a free (scanned) download, and they contain all the torque specs for every fastener and nut on the bike.
A 3/8" torque wrench that goes up to about 80 ft-pounds should be all you need for most work. A 1/4" drive torque wrench good for 20 to 30 ft-lbs would be nice for smaller allen head bolts (like the covers over the oil filter and other access plates. Use it for everything: the oil drain plug, spark plugs, axle nuts - every fastener on your motorbike needs to be correctly torqued, because your life depends on it.
Again: its not a motorcycle specific tool, but it is a necessary motorcycle tool.
The one tool that is perfect for its job usually comes with the yamaha tool kit, hidden in the storage compartment if your bike has one: the spanner for adjusting the monoshock. If you dont have the spanner, nothing else comes even close.
Last edited by KCW; 07-25-2019 at 09:53 AM.