CBR600f uneven jumpy/idle

[john24ssj]

Hello everyone,

I just bought CBR600f 2001 and it's lovely only has 10000 on the clock. The owner did not ride it much over past 5 years he only did 900 miles and it's been sitting in a garage for the last 10 months before I bought it.

Now there is a small issue with engine not running evenly, at higher speeds it's hard to tell but at lower ones and idle you can feel it. I've got a video of the idle and you can see the bike idles at 1000rpm but keeps jumping to 1100rpm which when riding at lower speed is very annoying.

This is my first fuel injected bike but it does not seem right. Any ideas what could be the possible issue?
Thank you
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Bikes: Honda CBR600Fi, Kawasaki ER5

[jaffa90]

Your bike has many sensors giving info to the e.c.m. (brain).
Have you seen the F1 light up at all?
https://cbrforum.com/forum/general-tech-9/fi-light-2001-cbr-600-f4i-151306/
It could be just a bad connection from a sensor or at the e.c.m.

[john24ssj]

[jaffa90]

Some early F.I. models have idle adjustment like the x11 and mine,
yours varies so it could be the t.p.sensor or a temp sensor.
Your bike revs from 1,000rpm upwards without hesitation so why the 1300rpm recommended is crazy unless it`s an oil feed or charging system that needs it ?????
On cold start mine revs at 2,000rpm then slowly goes back to 1,000rpm, so a sensor could be signalling a colder engine.
It`s electronics now so expensive equipment is needed to find out what signals the e.c.m. is getting.

[Hong Kong Phooey]

I'd be tempted to do a full service including fresh fuel and take it for a blast. What's the battery voltage like?

You might also want to check the condition of vac hoses, tank breather and airbox plus rubbers.

Digging any further might involve cleaning and balancing the starter valves.
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'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8

[Matt B]

[jaffa90]

[Matt B]

[john24ssj]

Due to real shitty weather I was not able to take out the bike but I did ride it down the street and I don't think it's just an idle issue in first and second gear around 2000rpm the bike was jumpy and juddery, not much but enough to notice it was not smooth. If felt as the bike was trying to readjust itself and was spiking the revs.

I will take it today to add some petrol to it and will see how it goes. Also can of seafoam has arrived so I will add it to the petrol as well.
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Bikes: Honda CBR600Fi, Kawasaki ER5

[john24ssj]

I feel quite disheartened, I rode my new bike in to work this morning and I did not enjoy it at all It was an awful experience.

Anything below 3500rmp the bike is jumpy/lumpy and juddery, it tries to lurch forward and then stops. It made for a very unpleasant ride.

4000rmp and up it was beautiful, tons of power and all was smooth. I think it might a vacuum leak or something, it feels like the engine is trying to adjust/compensate for something.
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Bikes: Honda CBR600Fi, Kawasaki ER5

[Hong Kong Phooey]

Don't discount the coils. I had a stutter at low rpm, which was eventually traced to a single dodgy coil by comparing resistance between them all.

It took ages to discover because tipping a whole bottle of redex in the tank got rid of it so I thought it just had to be fuel system related. It was only after stripping and cleaning the carbs that I looked into the ignition system.
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'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8

[john24ssj]

Took the bike home but this time I went on a dual carriage way then motorway and it was absolutely lovely. Did 80mph even 90mph and no hesitation or anything at all from the bike and everything was super smooth.

But the moment you go down to lower speed and below 4000rpm the bike was jumpy

Not sure if to just take it to Honda garage or try to check it myself.
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Bikes: Honda CBR600Fi, Kawasaki ER5

[john24ssj]

[Hong Kong Phooey]

Denso, used in loads of bikes.

There's a primary and secondary resistance, 11k or 11.2k from top of my head, I'll check later.

Main thing is one might be different from the rest at room temp. That'll be the one to replace. I bought 4 second hand for peanuts.
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'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8

[fatjames]

I'd be very tempted to go back over the basics with this issue. Did you have a chance to service it and add fresh fuel?
I'd also check the chain tension and tyre pressures (just to be sure).
I know it's a carbed bike, but a good thrashing could well help - get the bike up to temp first though.

[fatjames]

oh, and obviously increase the idle to the manufactures recommended RPM. (again, once up to temp)

[john24ssj]

[chris-red]

Could be an air leak, I don't think it is electrical, all my experiences with electrical gremlins it's never been rough low done and better higher in the rev range.
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Well, you know what they say. If you want to save the world, you have to push a few old ladies down the stairs.
Skudd:- Perhaps she just thinks you are a window licker and is being nice just in case she becomes another Jill Dando.
WANTED:- Fujinon (Fuji) M42 (Screw on) lenses, let me know if you have anything.

[Hong Kong Phooey]

HT coil resistance checks:
primary 1.1 to 1.5 ohms
secondary 11.4 to 11.8 K ohms
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'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8

[Paulf]

Hi low speed or idle problems can be many things, I note you say it Fi honda motorcycle. Common fault with honda FI bike is IAC valve (Idle Air Control) valve, a reset is recommended according to honda workshop for small bikes I.e. 125 fes, sh, pcx, etc could apply to big bike. But also valve timing, spark plug, ignition timing ie pulse generator, induction pipe leak, ecm, faulty ignition coil are possible causes. IAC reset is easy though but worth systematically working through the other possible causes first. I can tell you the process for the smaller bikes as I have said do not know if it translates up to larger bikes. But successfully performed on my 125 fes 2006 vintage and your bike is younger.

[john24ssj]

[Paulf]

Well yes in a way. You short out the dtc (diagnostic trouble code) connector the red connector close to battery. Switch ignition on remove the short link, then short out you engine temperature connector. Then start engine and do not touch the throttle and let the engine run until the rad fan kick in. If you are interested in giving it a go I will post the exact procedure as written in the honda workshop manual for fes 125 as stated it is pgm FI with injection no carb. I heard talk of carbs but this is for an injection systdm so this is why I am unsure. This I believe depending on demand and the ecm is happy it supplies the correct fuel. With a carb bike it is not so fly by wire more mechanical response to demand from the throttle.

[john24ssj]

[john24ssj]

I checked the stored fault codes on the computer and got this. I don't know how to read it.

https://youtu.be/u6X9csSM3sU

It seems to be 2 codes 1 blink (0.5seconds) and then 9 blinks(0.5 seconds)
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Bikes: Honda CBR600Fi, Kawasaki ER5

[Hong Kong Phooey]

Faulty IAT sensor or wiring, try cleaning the electrical contacts before just replacing. Just check the procedure because I thought the engine should be running under 5krevs on the sidestand.

Not at home so can't confirm from the manual, but these are the codes.

https://stuntride.com/vbstunt/showthread.php/36775-F4i-FI-light-codes
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'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8