High RPM stumbles are 'almost' always fuel related. Run it wide open tilll it starts stuttering and hold it there for a second and then hit the kill switch. That will lock in the fuel condition on the spark plugs. Pull the plugs and see what they tell you. Even if it's electrical the plug condition will tell you which direction to go. (Fuel cuts out=lean plug/Spark cuts out=rich plug)

You have to know what your chasing before you can catch it.

 

You can see here what happened during the run. Its is NOT feul related
As you can see the mixture rise out of proportion when the stutter is at its worst. This tells us one thing: ignition is failing.

The mixture is fairly rich overall, but that needs to be attended when the stutter has been corrected. First things first.

the spark-plug story realy doe not work on a bike that has been reving and has been warmed up. As soon as you hit the kill switch the heat will quikly vaporise the feul that would be on the plugs, so by the time you have fiddled the plugs out they will always show dry and show the color they had before the stutter which is coffee brown (always has been on my bike on all checks). This trick ONLY works when a bike gets a cold start without igniting.

Am searching activly for a pulse generator at this point. Note my bike had a fair share of electrical problems that I had to resolve before getting it road worthy. (rectifier, battery, some faulghty connections and wiring, all has been checked with a digital Fluke scope and showed no faulghts or open circuits after refurbishing)

 

I gotcha.

We'll you've been working in this for going on 4 months now i guess you gotta it all figured out without any help from us so.....

Good luck.

 

Not so fast there grasshopper! Doing exactly what zaqwert6 said to do DOES work. If you'd like to argue with EVERY mechanic in the world about it, go ahead. It has nothing to do with vaporizing fuel off of a hot spark plug and everything to do with seeing the DEPOSITS left behind on the plugs. Mechanics have been doing this since the invention of the internal combustion engine. If your mechanic is telling you this get a new mechanic and now!

 

I am sorry if I kicked somebody's ego here, but do you guys actually read through the whole topic, or just read the topic title and then reply?

In my case fuel has been ruled out, three times to be exact. the third time by a professional tuner. There are no deposits on the plugs and there never has been. plugs have been changed also, and when you read the graphics on the run you can see what happens. The mixture gets rich as the rpms go up. that has to do with sparks failing intermittently. So when you do the oldest trick in the book on behalf of this subject you see what i already know for about 2 months now. and the run just proved it again. We did it all lean mixture, rich mixture, and both had absolutely NO effect, but you could have known that if you read the topic a bit....

I have a far more complex problem then just a small mixture problem, but that's the problem with most forums, people do not read and just want to be heard for some reason. If i then doubt such a reaction then all the sudden I am someone who is only into "knowing it all"?

Sorry for being honest, but if this is the way of reacting here then I pass....I am not here to argue, I am here to try to find anybody who had a similar problem or experience, no need for simple fix's that have been tried numerous times on my bike. If it where that easy i would never had posted anything on any forum caus i know how to maintain a bike, and i can fix just about anything, only this problem doesn't give up its secret that easily.

So please read that the tuner tried several mixture settings and jets before also he had to admit that there is a hard failure in my electrical system. His digital scope also told so.....He didn't believe me at first, just like you guys, but even he had to admit being wrong, why do youthink he took the effort in helping me a whole day trying to find the real problem??

 

Look , first off I did not say it 'was' a fuel problem , I simply stated that is most often the problem but either way the point I was trying to make was that IMO 'someone' needs to get back to basics with diagnosis.

IMO , this has gotten WAY over analyzed as the fuel and ignition system on these bikes is rediculously simple. It relies on only a handful of parts and really ,it's nearly a 2 cylinder in many aspects. If I couldn't diagnose and repair such a clear repeatable issue like this in a couple days at worst I would be amazed. I've had these engines running full tilt on an engine stand at a race track to establish base lines and diagnosis. They're just not that complicated in regards to basic operation.

You have undying confidence in your mechanics , which is fine normally, however you've been obviously chasing your tails for something like 4 months ?....on this thing which once again IMO , is rediculous.

Then you come here apparently in despiration and throw arrogance at those trying to offer help and are even indignant in regards to what you think you 'know' already except that you are in fact, still lost.

I didn't give a crap about your 4 months of 'knowledge' because obviously your still stuck so something is getting overlooked, therefore my attempt to help starts with begining basics and I made statements with no disrepect when doing so. Im not going to build on the work of previous mechanics who could not get the job done, what sense would that make. You might consider that before you trash the one person that might have thee answer your so desperately trying to find.

So again , I do wish good luck in your quest. I appolize for wasting your time...which apparently you have an endless supply of.

 

Sunday i crashed the bike pretty hard. I was on a roundabout and someone cut me off as he had not noticed me leaving me with 0% possibilty of a last second escape.

Police and ambulance where on the spot soon, the guy stopped and took the blame like a man, and fortunatly is well insured.

At home in my bed with a broken shoulderbone, which is a pain in the *** but in the end it could have ended much worse.

I do not now exactly what the damage is but from what i could see in the brief moment i got my breath and stood up it didnt look that good. Then it was off to the hospital...

When i get a picture will post it and then this topic can propably get a lock. I dont think it will be worth refurbishing it. This desicion is up to what i will be receiving for my cbr as a totall loss case.

 

Heal quick. Sorry to hear you had an off. Silver lining is you will probably be able to get a better bike...

 

Get well soon buddy. Maybe insurance will pay for a new bike now so your problem is solved.

 

Thanks for the kind words, insurance will pay, estimated damage is around 2600 euro, say roughly 2900 dollars. The other party admit their faulght so things should be settled soon.

I think i will get another bike yes. Beside the damage to the plastics also the frame and tank had scratches. It is still ridable so can sell that one aswhel.

Am already looking out for a replacement fireblade maybe a bit younger, though sc-28's rides fine too.

Will post my new bike when i get it, prommis!