Assuming you would like tips to increase the top speed of a Harley-Davidson motorcycle, there are a few things that can be done. Most importantly, if the bike is not stock, check with the manufacturer to see if any modifications will void the warranty.
One way to increase top speed is by installing a higher performance cam. This will change the timing of when the valves open and close, resulting in more air and fuel being drawn into the cylinders. A good rule of thumb is that for every 1 degree that the intake valve opens earlier, top speed will increase by 2-3 mph.
Another way to add a few extra mph to your top speed is by porting and polishing your cylinder heads. This involves opening up the intake and exhaust ports so that air can flow more freely through them. It’s also important to make sure that there are no sharp edges inside the ports where air could get turbulent and slow down.
If you have an older Harley with carburetors, one way to eke out a little more power (and thus top speed) is by jetting them slightly richer. This means adding slightly larger jets so that more fuel gets mixed into the incoming airflow. Just beware that too much fuel can cause engine damage, so it’s important not to go too far with this modification.
Finally, one other way to potentially pick up a few extra mph is by changing your final drive ratio. This is usually done by swapping out your rear sprocket for one with fewer teeth or your front sprocket for one with more teeth. Keep in mind though that this will also change how quickly your bike accelerates from a stop as well as how comfortable it is at lower speeds – so it’s important to find a balance that works well for you.