Horsepower reduction over time

[steved]

One thing I have been interested in is how quickly a bike's claimed HP will degrade over time. For example, a 1997 GSXR-600 left the factory with a claimed 103 HP, and a 1989 CBR250R had 44 HP.

Any rules of thumb out there or is the dyno the only way to any kind of figure?

[nudemetalz]

Well, I believe there's just too many variables to put a standard percentage power drop.
For example, it depends on whether the motor has been thrashed, had regular oil changes, been babied too much, what fuel is run through it etc etc.

Just my 2c


NDMZ

[SimJen]

two strokes often get quicker the more they loosen up before going pop.
No way of telling how much HP they will drop, if they will drop....

[onearmedbandit]

And some motors with some miles put on them will go up in hp (bedded in better etc).

An engine if looked after properly doesn't necessary have to lose any power.

[Motu]

HP also rises at a rate depending on how many stubbies consumed....

[onearmedbandit]

And on top of that a couple of well positioned 'performance' stickers will also give a noticable rise in hp.

[James Deuce]

You're also assuming they're all built to the same spec. 103HP +/- 10% is probably a better assumption.

[Bonez]

HP also rises at a rate depending on how many stubbies consumed....

You eat garments? Weird

[Motu]

Eaten my hat many a time - figurtively speaking of course.