when i watch videos of sport bikes accelerating hard, with the camera...

[wheatthins]

...pointing at the rpms, they let it? rev until right before red lining. if i want to accelerate very fast, should i do that? i normally shift around 6000 rpm. my bike red lines at 9000, and it goes up to 12000. kawasaki 550 ltd. 1982. is it bad for the bike?

[stomper79]

Most all motorcycles are made to be able to run 75% of their redline all day long which in your case redline would be 9000 so running the bike to 9000 then shifting is not that hard on it. In theary if you held your bike at 6700 rpm all day going down the highway it would not hurt it either.

[It'sThatGuy]

Sport bikes with high-performance engines have a narrow powerband. You start out on them and let the revs build up towards the redline and at a certain point you suddenly feel a huge burst of power. The faster the engine is going, the more horsepower it develops, so to get the most performance out of it you keep it revved up all the time.

In racing you're not thinking about how long your engine will last. So long as it finishes the race, you don't care how hard you are on it. There's an old saying that the perfect racing machine, car or bike, slides across the finish line in a shower of parts. If anything -didn't- break, it was built too strong and the bike could have been lighter and faster.

On a street bike, this kind of riding shortens engine life. It accelerates wear on rings, valves, cams, etc. That's beside it not being safe. 8^)

Your LTD is a cruiser. It's not meant to be a race bike or high-performance bike. It has torque in the lower rev range so you don't have to keep it revved up all the time. Yes, you can get better acceleration if you let it rev up to the redline. But it's not designed to do that all the time. If you do it all the time you're going to break something.

[Will]

Unless your engine is not being maintained, going to red line is fine. Just because the tach reads up to 12000 doesn't mean it will rev that high, and it would be bad to go that high above red line. I have a small two stroke, and it runs most of the time at 9/10's to red line, and is 20 years old.

[bikinkawboy]

Mull engineering is incorrect in saying all jap bikes have rev limiters. Newer bikes do, but not something as old as your bike. You engine will rev until the valves float, something that has the possibility of causing serious damage.

If you really want to or need to accellerate in a hurry, then run it to the red line. Otherwise, shift where you do and if you're not in a hurry, shift at a lower rpm.

[MullEngineering]

Another thing to consider is red line and the power curve are somewhat related but when looking for the best possible shift point, you shouldbe looking for a power graph or dynamometer sheet that might show you where peak HP is made. Red line is an area that many riders will assume is where the peak power is. Peak power is almost always made well before redline thus you will go slower by shifting in the redline area.

All Jap bikes have a rev limiter built into the electronics to prevent over reving to the point of failure. Getting into the redline area will not blow a good engine but since yours is is pushing 30yo, you might heed the warning to not pushing too hard unless you can accept motor damage as a result.