Fireblade engine - end of my tether!
gingerprince - 26/10/13 at 04:30 PM
Getting to the end of my tether with my Fireblade now! It's still running 25% down on power, despite seemingly ruling out everything!
It's been like this since I swapped the gearbox and TRT prop out over the winter. This thread follows on from an old wanted thread here, which
is the wrong place for it now: -
http://www.locostbuilders.co.uk/viewthread.php?tid=185046
So it's still running about 25% down on power, and power/torque curves go flat from 7000rpm+. I've ruled out as much as I can. I've
had it on a rolling road at Daytuner and ruled everything and more out again! I've ruled more things out since. And still it baffles me! So,
looking for any other ideas. Things done so far: -
* Replaced coil packs (with standard ones after initially trying stick coil conversion).
* Replaced old HT leads and NGK plug caps with OEM caps and new copper leads.
* Replaced spark plugs.
* Swapped out ignition pulse pickup.
* Verified reg/rectifier is good.
* Confirmed no issue with coil packs connected wrong way.
* Verified grounds.
* Replaced fuel filter.
* Stripped and cleaned carburettors (twice).
* Verified throttle butterflies opening all the way.
* Fixed cam timing (inlet was out by 1 tooth causing other issues).
* Verified good compression.
Then took it to Daytuner and ruled further things out: -
* Verified my checking of compression, cam timing etc was good.
* Removed silencer and verified nothing in there was choking it.
* Ran on rolling road, verified running poor above 7000rpm.
* Ruled out any wiring/earth issues by giving my ECU a direct earth to battery.
* Confirmed carb/fuelling is fine - despite being down on power, the AFR matched the plot of when I originally got it set up all the way through the
rev range.
* Confirmed no leaks on carb rubbers etc.
* Probably loads of other things I can't remember.
Damian's conclusion was that it wasn't consuming oxygen and must be the ECU not advancing ignition >7000rpm as everything else has been
ruled out. Didn't have one to hand to swap, so ordered one but it didn't turn up in time for a booked track day. So I picked one up from a
local breakers, and it still has the same symptoms 
So now that's everything seemingly ruled out!!
Since then on my latest track day I had some clutch slip symptoms, so I have upgraded it with new plates and stronger springs. Had a brief hope that
my issues might have been transmission, as if the clutch might be slipping enough to not transmit power, but not enough to accelerate the car
effectively as if at biting point (long shot, and unlikely, and turned out that way but needed doing anyway!).
I've also completely removed my Techtronics flat shifter from the loom, in case that was doing odd things, but alas no.
I'm not a religious person, but starting to wonder whether a quiet word with the man upstairs might bear some answers 
Seriously, I will be calling Damian again next week to see if he has any other ideas, but does anyone have any other ideas of things I could try
before it gets too cold/perpetually damp to road test any fixes???
Thanks
Frustrated of Leeds
r1_pete - 26/10/13 at 04:57 PM
Are you running a throttle position sensor? if so have you checked it? failure would interfere with the timing.
gingerprince - 26/10/13 at 04:58 PM
It's early carbs/ECU so no TPS.
mark chandler - 26/10/13 at 05:08 PM
Mine was like that when I ditched the standard air filter, put in a dynojet kit and played around with needle position and all was well.
I struggled to believe such a seemingly small change to the inlet could have such a drastic effect.
Slimy38 - 26/10/13 at 06:24 PM
quote:
Originally posted by mark chandler
I struggled to believe such a seemingly small change to the inlet could have such a drastic effect.
Without knowing much about cars (and only a little bit about bikes), I would agree with this. On my bike (Yamaha Thundercat) there is a tiny pipe
leading from the front of the bike to the airbox. It's too small to be a proper air supply, and the only thing I can think of is some sort of
pressure equalisation. But if it ever gets blocked or disconnected you lose a chunk of power and revs so it obviously got designed that way.
Is there anything you can do to get the airflow closer to the engines original application?
ReMan - 26/10/13 at 06:26 PM
So what air box/filter are you using?
Symptoms you describe are exactly that of mine without the air box
mark chandler - 26/10/13 at 06:48 PM
From his photo archive a box with K&N on the front.
Mine was similar although folded Ali with a K&N, destroyed the engine above 7000 rpm!
Needs new jets then.
gingerprince - 26/10/13 at 06:56 PM
Jetting should be spot on. It was setup with this configuration on rolling road last year and nothings changed on the intake or exhaust side. In
fact on the rollers this year the fuel mix followed the old one perfectly on the dyno, just with less power.
jeffw - 26/10/13 at 07:07 PM
Does it do it with the airbox/filter off?
Doctor Derek Doctors - 26/10/13 at 07:07 PM
quote:
Originally posted by gingerprince
It's early carbs/ECU so no TPS.
My carbed 919 has a TPS, what fire blade is it? Mine ran shite when I forgot to plug in the TPS after some engine work.
motorcycle_mayhem - 26/10/13 at 07:07 PM
Sounds like all possibles have been eliminated.
Modern petrol (full of radical mops, oxidants, etc.) will drop out polymeric residues if hanging around. Carbs have been stripped and cleaned, though
no mention of fuel pump (and/or) pressure regulator. Very long shot.
I'm stumped.
rick1962uk - 26/10/13 at 08:55 PM
its a shame your so far away its my job building these but the small things are always overlooked i will try to help out but its very hard with out
seeing it but i will give it a go
first are all 4 exhaust pipes the same heat
do the coil packs add up to 5 on the plugs 1 pack feeds 1 and 4 1 pack feeds 2 and 3
if one exhaust is cooler swap over the coil packs to ruel these out
take off the air box and put your finger in the carbs one by one and lift the slid and release they should go up smoothly and have a slight damping
on the way down also it you run it when you rev it they should lift up together
also i have seen the needles in the slides not fitted right so when you lift the slides just see if you can push up the needles dont push to hard they
should give a few mm
try these and reply with the results and i will try some other idears
rick1962uk - 26/10/13 at 09:02 PM
just had another thought have you had the carbs ballanced
ed1801 - 26/10/13 at 09:21 PM
My carbed fazer had a tps. otherwise it will only run a 2d map and that just won't be the case for a modern bike.
Can you measure the timing while revving, should change.
Edit:the 893 doesn't have one. How bizarre!
[Edited on 26/10/13 by ed1801]
mark chandler - 26/10/13 at 10:48 PM
893 the timing is advanced by the ecu
gingerprince - 2/11/13 at 12:55 PM
Finally managed to get myself 1/2 an hour in the garage, so ruled out a few more things.
quote:
Originally posted by jeffw
Does it do it with the airbox/filter off?
It's the same whether running Airbox/K&N or my original TTS sausage filter without box.
quote:
Originally posted by motorcycle_mayhem
Modern petrol (full of radical mops, oxidants, etc.) will drop out polymeric residues if hanging around. Carbs have been stripped and cleaned, though
no mention of fuel pump (and/or) pressure regulator. Very long shot.
Not done anything with the fuel pump, mainly because fuel mixture looked OK on rolling road, so assumed that it must be OK. Having said that,
I've been given another suggestion to rule it out. The thought being that the fuel pump might not be able to "keep up" under load, so
the float bowls are running at or near empty. I don't think it is this, as I'd expect to feel more pronounce jerkiness etc as you get when
you have fuel starvation - my symptom is everything feels/sounds OK, just doesn't accelerate enough. But the suggestion to rule this out is to
drive at full pelt, then cut the ignition when it's at 10krpm (I don't have a steering lock before anyone says 
). Then drain the float
bowls. If there's little or nothing in there it could be fuel pump. If/when we get a dry weekend day any time soon I'll give this a go.
I have no concept of how quickly fuel is consumed from the float bowls - would it empty in seconds, if not being supplied, or longer than that?
quote:
Originally posted by rick1962uk
its a shame your so far away its my job building these but the small things are always overlooked i will try to help out but its very hard with out
seeing it but i will give it a go
first are all 4 exhaust pipes the same heat
do the coil packs add up to 5 on the plugs 1 pack feeds 1 and 4 1 pack feeds 2 and 3
if one exhaust is cooler swap over the coil packs to ruel these out
take off the air box and put your finger in the carbs one by one and lift the slid and release they should go up smoothly and have a slight damping
on the way down also it you run it when you rev it they should lift up together
also i have seen the needles in the slides not fitted right so when you lift the slides just see if you can push up the needles dont push to hard they
should give a few mm
try these and reply with the results and i will try some other idears
Measured exhausts with infra red thermometer at hot idle. All were ~350c-360c at 6 inch ish from the block. I'm guessing that's close
enough, given the inherent inaccuracies with reader, reading location, thickness of manifold etc!
Definately got 1 coil pack to 1+4 and the other to 2+3. Have tried reversing polarity on one and both too, not that I believe this would make a
difference - it's just a coil?
It's been tried with 2 sets of regular coils (and stick coils but we won't go there!), so I'm confident coils are OK.
quote:
Originally posted by rick1962uk
just had another thought have you had the carbs ballanced
Carbs were balanced when it was setup on the rollers last year. Haven't been done since, but idle is reasonable and this is usually where an
inbalance shows I think?
quote:
Originally posted by mark chandler
893 the timing is advanced by the ecu
Yep, it's 893 ECU, carbs have no TPS so advance is set by RPM only AFAIK. The block is actually a 918 block, replacing my original 893 which
went bang. This block however is the one I had setup on the rollers in this configuration, so that isn't the issue.
Any other suggestions most welcome - thanks for all the suggestions so far.
Brackers - 3/11/13 at 10:33 AM
Hi Damien good guy he balanced carbs on my Indy Blade. On the air box front, mine has standard blade air box and have been told they run better with
standard air box. Guess would be good idea to make this standard first and then get Damien to setup again?
gingerprince - 19/1/14 at 05:32 PM
I think I might have fixed it! Rolling road had concluded it must be ECU. So I'd tried another and had no luck. Then I tried a third
just in case (borrowed from Jossey on here - cheers David) and that didn't fix it either.
So, today I replaced the wiring and connectors between the pulse generator and the ECU, and I've seen the rev limiter for the first time in over
a year My suspicion is that the signal was breaking down at higher RPM so the ECU didn't know to advance correctly.
Too wet on the road to be 100% sure, but it certainly felt like it was picking up better. Fingers crossed for a dry day next weekend so I can give it
a proper road test.
I hate wires!
[Edited on 19/1/14 by gingerprince]