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Discussion Starter #1
Ok guys, first up the bike.

07 cbr600rr
Hrc Ecu, loom, and cams.
Velocity stacks.
Full system arrow.
Ngk imr9c-9hes plugs.

I think that's about all that's relevant.

Long story short, my bike won't rev beyond 13200 rpm once it is warm. Cold will also only pull to about 14500. The limiter is set at 15800.

This is not a subtle sort of 'it wont rev any harder' it is a full blown rev limiter.

It started out feeling like a small stutter, barely noticeable at around 13k rpm, and I also at this time could not rev beyond 15k rpm. The small stutter grew stronger, to the point where the bike had to fight past that rpm range, then it Would break free and power on as normal. I should at this point say that these issues got worse as the bike warmed up. Cold out the pits it would rev all the way beyond 15k rpm. A few laps later the stutter would begin and progressively get worse...

The issue now happens at all temps, the issue being what feels like a lowered rev limiter. At best 14500rpm when cold, but after only a minute on track it's down to 13200.

I have replaced coils, plugs, done valve clearances, a leakdown test, replaced the reggy Rec, removed and replaced the dash, had my ecu in another bike which did not replicate the same problem, have normal charge rates hot and cold, a fully functioning stator.... Most recently tested the cam, crank and throttle position sensors, even put another throttle position sensor on just to check. Bypassed the kill switch just incase, disconnected the thermo fan and left handlebar switch block. Zeroed the ecu tune.

None of the above has had ANY effect.

Any one heard of an issue like this before?
The severity of the issue, and the relationship with heat has us looking around for spark/electrical related issues, as apposed to fuel blockages and such, which would not be so pronounced.

I and every one around this bike including some very reputable mechanics are stumped.

Any help and suggestions are welcome.

Thanks guys.
 

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As an aside, it is also worth check that the speed sensor and knock sensors if still fitted are working correctly. (not sure what the hrc ecu needs... but stock ecu needs both of these for ignition timing at high speed / rpm)
 

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Discussion Starter #4
Thanks nico. Knock sensor is removed. Not sure about speed sensor, I don't have a speedo but will look for the sensor.

Not sure about ignition timing. The Hrc ecu changes this even when set to the 'zero' setting. Hrc will not tell you why changes they have made to the standard map either. But will certainly check and see if it goes all spastic at high rpm...
 

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Discussion Starter #5
For what it's worth. Will replicate in the stands in neutral. So doubt the speed sensor is going to do anything if indeed it is there...
 

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Fair enough... I would still look at the ignition timing though

Have you tried plugging a standard ecu into your bike? You may get a DTC.... and if not, at least you would know what the timing is supposed to be.
 

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Discussion Starter #7
Hrc still appears to have some codes. The light was flashing away last night when I forgot to plug the tp sensor back in.

Will check the timing, although really not sure how that will help, standard ecu or not. I may know that it is out, but thats not going to tell me why... I already know thenissue is spark related (as apposed to fuel)
 

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Yes, but if you know that its a timing issue then you can have a look at your sensors and wiring, instead of coils/igniters and plugs...
 

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Discussion Starter #10
Never heard of one of those.

Have put 2 new sets of plugs in (just incase) fresh coils as well.

Got a mechanic coming tonight. Will see if he can't test the timing for me too.

Tested the cam and crank sensors, and they are ok, although specs are only given under certain conditions, and that is certainly not at 13k rpm, so hard to know for sure... Tempted to replace them anyway and see what happens
 

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You use them for testing the insulation in various components in the ignition system... they are not common though due to the cost of buying one compared to the cost of replacing the suspect components...

If you have new coils and plugs and the timing is correct, the last thing I would suggest is putting an oscilloscope on the power going to the coils and having a look for transients with the bike running. You may be getting interference from the ignition system feeding back into the ecu... and this can be frequency specific... google emi emc for a bit of info :)
 

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When the cams were changed... Was the OEM cam sensor pulse rotor changed to the HRC part ?
 

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Discussion Starter #13
Honestly, no idea. The bike is an 07 and has been racing with the Hrc parts since then. I got it in january running fine. I'd say that's been changed as it was built by a very professional team here in Australia...could be wrong though.

No luck on the timing. Bit hard to read when it's running on a rev limiter.

Chasing down a crank and cam sensor, as my dash reads incorrectly when the problem occurs, my thought being the Ecu is receiving a false rpm reading, which only come from cam and crank sensors...
 

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I cant see it been the wrong rotor then.. coz the cams have been in there for a while. (Wasnt sure if you had just fitted the kit bits.)

You say the mil lamp is flashing? Can you find out what codes are stored in the ECM?.. We really need to know this first.

It does sound like a cam or crank sensor problem tho.. You may have to start by replacing one, then the other to rule them out, if theres no relevant codes stored.
 

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Discussion Starter #15
Did I say the mil was blinking somewhere in there? Oops. Maybe intested it with removing a connector but I'm not getting it for this rpm miss.

Just replaced cam and crank sensors, from a known working race bike. No luck.

Next up, fuel issues.
I noticed that bring the revs up slowly, only using as little throttle as needed i will climb to about 14500rpm, and have a normalize sounding rev limiter. Bury the throttle though, whether from 2k, 10k or 14k, and the bike breaks down hard at around the 13k mark (it's hard to be certain like this, as the rpm gauge goes up and down around about 1500rpm each way)

As I have changed the tp sensor, I'm gonna look at secondary injectors, fuel pump, map/maf sensor....

Anyone else got bright ideas? Tryng to take a lot on board at the moment, this problem had been here for a while, and my head is almost full.
 

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Did I say the mil was blinking somewhere in there? Oops. Maybe intested it with removing a connector but I'm not getting it for this rpm miss.

Just replaced cam and crank sensors, from a known working race bike. No luck.

Next up, fuel issues.
I noticed that bring the revs up slowly, only using as little throttle as needed i will climb to about 14500rpm, and have a normalize sounding rev limiter. Bury the throttle though, whether from 2k, 10k or 14k, and the bike breaks down hard at around the 13k mark (it's hard to be certain like this, as the rpm gauge goes up and down around about 1500rpm each way)

As I have changed the tp sensor, I'm gonna look at secondary injectors, fuel pump, map/maf sensor....

Anyone else got bright ideas? Tryng to take a lot on board at the moment, this problem had been here for a while, and my head is almost full.
test the flow rate and pressure of the fuel pump...

50 PSI operating and 167ml every 10 seconds @ 12V

You can also try running your injectors through an ultrasonic bath, which is not a bad thing to do every now and then either way.

And the bike uses a MAP sensor, if it was malfunctioning you should get a DTC, if its just giving slightly off values the performance will be out all over the shop and quite noticeable. The bike will have a tendency to bog and stall when going WOT at idle.
 

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I've been thinking about this one a bit....

I very much doubt your problem lies in the fuel system... or the ignition system really...

I honestly think your problem is being caused by electrical noise. If you happen to know an excellent auto elec (preferably with a background in electronics) it would be worth having them investigate the issue...

For the DIYer in you: First off check that all your earth points are free of corrosion, you may even want to replace the star washers just to make sure you have a good electrical connection.

Then if that doesn't do it you basically need to look at every pin on the ecu with a fast (min 100MHz) oscilloscope and look for spikes that shouldn't be there.

Alternatively, if you happen to know someone that has a harness you can borrow that should rule out 75% of the possible areas that may be causing your problem. The rest is sensors.
 

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Discussion Starter #18
just because i hate finding these niche threads online with no answers, i thought id better post up...

We never did find an absolute answer, but we did have the engine let go.
coming out of a 3rd gear corner it began stuttering badly at about 11k rpm, and wouldnt pull through, so i shut it down. in the pits, it wouldnt turn. later when it cooled, it fired up.

we pulled it down and found a main bearing had let go and dragged 2 pistons in the bores and scored them badly, those same two rods had shagged big ends. the crank had a slight warp too.

our theory was that either the bearing was gone and bent every thing else, or the crank was warped and shagged the bearing etc. imagine spinning a coin. it is fine most of the time, but spin it too fast and it wobbles badly and falls over.

we scapped the engine, got a new one, and the problem went away.

so it was DEFFINATLEY mechanical.

not good news, but thats all i have.

hope this helps someone in the future.
 

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Certainly not an ideal outcome... I don't know what could have caused your problem besides valve problems though, and you would expect to hear it if that were the case. :dontknow:

At least you have it up and running again!
 

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Discussion Starter #20
yep, it was a strange one... guessing the previous owners rebuilds had been half arsed and the bottom end was just worn out.

will never know.
 
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