With this post maybe some of you will feel provoked a little bit, but let me ask you if you're really sure that the from Kwaki given hp for the Ninjette is correct in every way?
Based on many judgments from German courts against some car producer I'd read in the last time I would like to say: NO they can not...
The second thing which made me thinking is that the Benelli 302, a twin also, with better values than the Ninja 300 in each case has a power output given by 37 hp while Kwaki talks about 39 hp and dyno runs showed at the rw ~33.5 hp.
So now we let the guideline 95/1/EG from the EU be a part of the game and there is a very clear description about the difference from engine to the loss at the rear wheel.
The average values for all those losses are:
Primary drive - 1.5%
Gear stage - 1.5%
Chain drive - 2.5%
Friction losses - 1.0%
Please keep in mind that this values are average values only and may be higher or lower in some cases.
But one thing normally is very clear, if the loss of power at the rw is higher than 10% then there must be a bad maintenance at the chain drive.
Important to know especially for Americans, since you don't know it otherwise, is that in Germany all dyno runs are automatically calculated to crank hp by DIN-Measurement.
But what does this mean? Nothing else than that the real crank hp from the Ninjettes should be (based on all the dynos one can find in the I-Net):
250-Carb-Model = ~28 hp
250-EFI-Model = ~31 hp
300-EFI-Model = ~36 hp
What also means respectfully contradicting @
marc99 that the Italian Ninja 250 race bike should have around 42.5 hp at the rw (by the way with your calculation model NO American car or motorcycle would ever pass any of the European tests, or they show fake numbers what nowadays anyway is the new normal). What is left when you subtract around 40%? But please don't believe in the stupid talk of me old boy with some little experience, just only read the official given guidelines.
I don't doubt your knowledge @
marc99, but many times in my long live I've seen horses puke...
Also it's important never believe only one opinion since every thing got two sides and to let you know a part of my background please take a look here:
http://www.alpina-archive.com/?page_id=171 my world is the world of cars, so in case of mc's I might not be right every time, but the principal of engines is always the same, or at least should be.
@
micoulisninja, I didn't say that there is no need to change the valve springs, please take a look at my writeup and you'll see the parts number for them. The only thing I did was to translate the given information from one of the most experienced tuning company for Ninja 250 race bikes. So I would beg you please for more information to contact them.
@
garth285 already pointed out where the parts come from: the 2004 ZX6-R and others, so there you should look how high they are able to rev.
Or maybe look at the real old 250/400cc-bikes which did rev up to 20000 rpm, maybe there you can find some valves in the same size like the Ninja. But also it's important, like you said in another post I'd read from you, take good care that the springs are not to strong bc then they will not only limit the ability to rev but also hit your valves into the seat what's never a good solution.
Also to answer the question about the ignition advancer in the EFI-Model:
my Ninja is EFI (please take a look at the attached PDF).
But there is one difference to keep in mind: the Thai-Version has 38 deg btdc @ 6000 rpm while the European model has 40 deg btdc @ 6000 rpm.
To give some information about the temperature, since I have the Koso RX2 instrument I'm able to read the value of my temperature. After installing the ign adv I carefully watched this and from what I saw, is that the value went down by around 8 degrees celsius. I think it's well known that a wrong ign timing will make an engine overheating but also that the right value will keep the temperature normal (low).
@
marc99 - your puller doesn't work with the 250 Ninja.
I hope that I could satisfy all your questions, so I'll step back into my cave now and say vaya con dios.
