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Author: Subject: Fireblade - not running right
Banana

posted on 1/4/17 at 05:40 PM Reply With Quote
Fireblade - not running right

After sorting lots of little issues out with the car, i still have an underlying issue it seems, with the thing not running 'right'.

It sounds hesitant when slowing increasing revs at idle, not to mention the the revs are hunting when held at a constant point - say 3k rpm.

It drives ok, but you can tell its not smooth, and has a rough/flat spot around 5-6k. Not to mention a horrible drone, which im sure is related.
I have a standard Blade can, but it really is a horrible sound in the mid range. (reminds me of that sound you get if there is no airbox)

I've had it rejetted and setup by Andy Bates recently, so i assume its not carb related..
Plugs look correct tan colour
New HT leads.
Standard air filter back in, as i heard K&N can cause issues.

Next i will try the coils, but that will be a fair bit of expense on the off chance it will help.

If the coils were to blame, wouldn't the plugs be showing signs of not running right?

Any other suggestions? The sun is out, and im still tinkering..


(If there is any one local to me with a set of coils i could try, that would be great..)

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CosKev3

posted on 1/4/17 at 05:48 PM Reply With Quote
Coils usually fail totally resulting in a misfire, rather than slight running issues like you have .

Do you run it on normal unleaded or super?

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ReMan

posted on 1/4/17 at 06:06 PM Reply With Quote
so was it rolling roaded with k and n or standard air box?

As mentioned it does not really sound like coils. Though possibly an HT lead leak. look under the bonnet at night !

The 5-6 K flat spot is not that unusual I believe, a bit of a characteristic before the power really kicks in!

And what fuel pump are you using?



[Edited on 1/4/17 by ReMan]





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Banana

posted on 1/4/17 at 07:10 PM Reply With Quote
I run on super unleaded.

No difference when i fitted new leads.

Standard Blade pump - as Andy recommended.

He didn't rolling road it (he doesn't have one) but assures me he has done so many of these, and knows the exact setup. Which i don't doubt.
It did have the K&N on when he set it up, but i had barely driven the car at that point, so hard to say if its always been like this or only after he jetted it.

I had a similar issue on my old ZZR1100, and it turned out to be the little carb equalization hose wasn't getting the same ram air as the main intake.

I know Blade aren't pressurized, but ive read a lot about K&Ns causing issues. However, lots of the guys here seem to run with just a sausage filter, so maybe they aren't to precious with regards to airflow..

It feels like its running lean, so tried covering half the intake pipes, but made no difference.
Thats what made me wonder about coils.

[Edited on 1/4/17 by Banana]

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CosKev3

posted on 1/4/17 at 07:28 PM Reply With Quote
I think I would get it on a RR before just chucking parts at it,get the AFR logged and tell them where you can feel the issues and at what revs etc.

If they just do a flat to the boards power run it might look ok on the graph and feel OK to them

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Banana

posted on 1/4/17 at 07:37 PM Reply With Quote
I agree, on full throttle it makes the problem go away

You're probably right, but i will see what AB says before throwing more money at it on RR setup.

Do you think poor setup could cause this god awful drone at 5-6 k?


[Edited on 1/4/17 by Banana]

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CosKev3

posted on 1/4/17 at 08:22 PM Reply With Quote
Not sure about the drone tbh,but the slow revving etc could well be down to set up/needle shape/height etc.

What's the drone sound like?

I had a noise on my R1 eng at circa those revs but it was more of a quiet/dull knocking, suffice to say it spun a crankshell and knackered the engine

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Banana

posted on 1/4/17 at 09:32 PM Reply With Quote
Just an unpleasant, slightly louder, resonance/tone at about 5-6k, Sounds a bit like the air box is not on or something.

I've got a little Yoshi slip on that i've never fitted, so will try that, see how much is down to the end can.

[Edited on 1/4/17 by Banana]

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MikeRJ

posted on 2/4/17 at 09:40 PM Reply With Quote
My CBR900RR ran quite badly when I first got it and it turned out to be the original HT leads breaking down. You can replace the leads separately, they screw into the coils/spark plug caps but if original they are also glued which makes them harder to remove.

Noise in the mid range may well be the slides in the carbs rattling. I modified the airbox on my bike to remove the partition in the middle, which is primarily to create a resonance chamber to suppress noise, and I thought I'd broken something when I frrst took it out. Spent ages ensuring the exhaust headers were sealed (sounded a little like all the headers were leaking) but finally realised it was from the carbs themselves.

Another possibility is the cam chain tensioner may be on it's way out which can create quite a harsh noise at certain RPM as the timing chain flaps around.



[Edited on 2/4/17 by MikeRJ]

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Banana

posted on 3/4/17 at 07:45 PM Reply With Quote
Thanks for your input, but i do believe i have sorted it.

Whipped each main jet and emulsion tube out, gave it all a good blast with carb cleaner, put it back together and it seems to have sorted it!

I've only ran it stationary on the drive, but it revs so freely now. Cant wait to test it, as i don't think ive actually driven this yet without there being some kind of little issue.
Will be good to see what its got


Mike - did you do the 'viking mod' by any chance?

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MikeRJ

posted on 12/4/17 at 08:49 PM Reply With Quote
quote:
Originally posted by Banana
Mike - did you do the 'viking mod' by any chance?


Sorry for late reply, yes I did. I initially used the filters that came with the Factory Pro jet kit, but didn't really like the way they fitted so ended up with a Pipercross filter that fits like the original but has far more area.

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