is free reving bad?

just dont bang it off the rev-limiter over and over.
But I cant imagine free reving for an hour would be a good thing.

i dont think it does any harm. as stated above, stay off the rev limiter and dont rev it for hours on end

its not a good thing, but doing it just a little shouldnt hurt anything, like they said just dont rev too high.

It shouldn't hurt it. A motor functions the exact same whether you have a load on it or not. The only difference is the that the engine will build rpm's faster. Just don't over rev it and you will be ok.

It can hurt if done repeatedly, let me explain.

The first piece most would not expect to encounter damage is the manual transmission, autos are different. When you free rev you engine while not in gear, you are still spinning the crap out of the transmission, but not entirely normally. The lubrication system of a manual trans is mechanical, meaning a manual transmission relies on itself to spin entirely to lubricate completely internally. Repeated high revs at a stand still in neutral can be bad over time.

Next, with no load on the engine, the computer will run a leaner fuel mixture, and not adjust the timing as it would if normally driving down the road. This means that your standing still high revs are running the engine leaner than normal, which over time, causes damage.

Lastly, as said above, with no load on the engine, the computer knows this, so the throttle response you feel and hear while standing still is different than what you would feel and hear while driving down the road.

It other words, it's kinda pointless is what I'm saying, even if it does sound cool. If you need to rev the engine while standing still, do it sparingly, and keep the revs below 4000rpms.

On a side note, I don't know if the owners manual states anything about free revving while not it gear driving down the road, but I can tell you that all high performance motorcycles have it in the owners manual, and usually stickered on the tachometer or gas tank, to not free rev the engine, as it could cause damage, for the same reasons as above.

Free revving doesn't do anything to the tranny if you have the clutch in.

:damnit:

I give.

The only problems I can think of is that the main/rod bearings are designed and broken-in with a load on the motor. Like everyone else said keep it below 5500 (good safety buffer) and you should be fine.