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Re: idle speed problem at start up

14K views 25 replies 10 participants last post by  nikoszx12  
#1 ·
Re: idle speed problem at start up

I have a 2002 Bird that does something weird (or maybe not) on start up. When I first fire it up when cold, it revs to about 1800-2000rpms for about a minute (that seems normal). Then, the idle starts dropping (also good). Problem is, it keeps dropping way past the point of normal idle to about 500 rmps at which the engine almost stalls and starts knocking. Just as it's about to stall, it starts climbing back up and settles into a normal idle.It's always done this but it's bugging me. A coupke of times I've kept my hand on the throttle to make sure it doesn't stall.Does the autochoke need to be adjusted and if so, how do I this? Or is this just normal Bird behavior?Btw, when the Bird is warm and restarted, does not do this. Just settles into a normal idle, set around 1200rpms.Bird has 42k miles. Valves have never been checked and as far as I know, original spark plugs. Thanks in advance.
 
#2 ·
Re: idle speed problem at start up

Valves never checked? Original spark plugs at 42,000 miles? Do you know this for sure? The "normal idle" is too high.

Sounds like the thing just needs a full service.

The ECU can only compensate for so much.
 
#3 ·
Re: idle speed problem at start up

You can adjust the idle, it's a "white" do da on the left side of the front faring. I would't open up a can of worms and start with the most complicated and perhaps expensive approach before the simplest. It should fast idle when cold and settle down to 1100+-50 when the temp gage shows and she's ready to ride. IF Birds all fast idle till warm. I've never had an issue but of course my Bird of over serviced and maintained. However, this being said, if your Bird needs servicing, then do it.
 
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#4 ·
Re: idle speed problem at start up

Guess my original post wasn't clear. The idle is correct at about 1200 and she idles there just fine when warmed up.The problem is that she fast idles on start-up and then drops down way past the normal idle, almost stalls at around 500 rpms and then the ECU kicks in and brings her up to the normal idle.So, my question is, why are the rpms dropping down so low before being brought up to the correct idle?And yeah, I'm sure on the valves and plugs since I've owned her since 8000 miles. She pulls hard and runs perfectly. But yes, going to bring her in for a full service at 50k. But am curious about this start-up quirk. I'm not sure this is normal.
 
#5 ·
Re: idle speed problem at start up

Image
http://img.tapatalk.com/d/14/01/12/3a2e6eju.jpg[/IMG. I can't answer your question but have you adj your idle up or down in any manner?


Sent from my iPhone 5 using [URL=http://tapatalk.com/m?id=1]Tapatalk[/URL]
 
#7 ·
Re: idle speed problem at start up

Your first post was perfectly clear.

You asked for advice...

Warm idle is not correct at 1200rpm, that's too high. It's been set artificially high to stop the bike doing what it wants to do - which is stall. The factory-designed relationship between the automatic cold-start idle (for which there is no adjustment) and the normal warm idle is proscribed in the factory manual.

The ECU is trying to compensate for the cumulative effects of poor maintenance.

That's why you have to rev the bike immediately after it comes off the cold-start high idle.
 
#8 ·
Re: idle speed problem at start up

Your first post was perfectly clear. You asked for advice... Warm idle is not correct at 1200rpm, that's too high. It's been set artificially high to stop the bike doing what it wants to do - which is stall. The factory-designed relationship between the automatic cold-start idle (for which there is no adjustment) and the normal warm idle is proscribed in the factory manual. The ECU is trying to compensate for the cumulative effects of poor maintenance.That's why you have to rev the bike immediately after it comes off the cold-start high idle.
Not disregarding what you are saying. It makes sense and I take your point about maintenance.So, it will go in for maintenance. Plugs, valve adjust, throttle sync. Anything else I should be looking at?
 
#9 ·
Re: idle speed problem at start up

Look, if you tear it down and you find out that the spark plugs are still good, valve clearances are within spec, air filter is clean, throttles balanced and all of that, then it's time to look for something actually being wrong.

Your problem is likely caused by everything being slightly - or more - out of spec. I'm not knocking your maintenance, it's just based on what you said.

I had exactly the same problem. I don't think the PO of my '00 had ever serviced it - the log-book service stamps ended about 6 years previous.

In order of priorities, I'd go:

  • Clogged air filter
  • Plugs past their service
  • Throttle bodies out of balance
  • Valve clearances out
and replace oil, filter and coolant as you would normally.

For me, once I'd sorted those out, the bike ran just as it should. With a few hiccups on the way, but those were down to me.
 
#11 ·
Re: idle speed problem at start up

What service do you do every 3-3,200 miles? I do valves when I do plugs24-30,000 kms. I have a decent service schedual after 210,000 kms. But I'm not riding as often these day, but it's winter so that's normal for me. I also run some fluids others don't. Motul Dot 5.1 hydraulic, Motul Expert professional coolant, which I flush every two years. I also, contrary to Brit opinion run Motul 7100. I change oil every 5-6,000 kms or so. Sometimes it all needs to be done at the same time. Then she's laid up for a few days, no problem. These engines are as good as they get and with proper maintenance and winter storage they run great as well. It's interesting, stealing this thread, I've never had many of the issues others have on this forum. I think it's b/c I just don't do my own service. The biggest, most time consuming and pricy service I did last Jan when I replaced the cam chain, guides and all the do dahs, and did every service necessary. Forks off for total service, Penske out to service, valves, plugs, bearings front and wheels, cush drives, chain sprockets, and a few other extras such as replacing the fairing foam insulation, (difficult to find). There you go. when money is not object :) joking, and you love your Bird, the sky's the limit when it comes to service. All I need now is new tires and to stop going for weekly treatment, 4 on, two off and to be delared "free" to ride again.
 
#12 ·
Re: wax unit

After doing more researching, I suspect the problem may be with the wax unit.Does anyone know if a defective wax unit would give me the symptoms I described above (bike heads into a stall on cold startup before revovering and idling)? Not discounting looking at valve adjustment, plugs, etc. but just want to cover all bases. Thanks.
 
#13 ·
Re: idle speed problem at start up

I doubt it's the wax unit as you say the idle initially run up for you, then drops back down - that's the wax unit at work.
 
#15 ·
Re: idle speed problem at start up

ok, thanks. Tried to do a cold start this morning, revved up fine and then it just nosedived into a stall. So, guess I'll cross the wax unit off the list.
 
#16 ·
Re: idle speed problem at start up

If you start the bike and help it rev up for about 10-20 sec. does it go into a normal idle? Or as you said does it at 120 still idle like crap? Also have you checked the loom fix? It does happen on later FI's also....chance is less likely but can happen...

When its cold here in Salt City I have to help my girl for the first few seconds so she gets the oil going then she purrs like a kitten...Don't worry. On this site you can fix anything!
 
#18 ·
Re: idle speed problem at start up

If you start the bike and help it rev up for about 10-20 sec. does it go into a normal idle? Or as you said does it at 120 still idle like crap? Also have you checked the loom fix? It does happen on later FI's also....chance is less likely but can happen...When its cold here in Salt City I have to help my girl for the first few seconds so she gets the oil going then she purrs like a kitten...Don't worry. On this site you can fix anything!
Thanks for the moral support :)So, if I help it rev, it will hold the idle. The idle is slightly lumpy, with the tach needle bouncing a bit,, even when warm so the starter valves definitely need to be synched.But at least it doesn't stall. If I leave the throttle alone, it wants to stall. Before I sync the starter valves, gonna have the valve clearances checked. It's never been done before and ditto with the plugs. I've been good about changing my air filter on time, oil and filter changes, running Seafoam through the tank once in a while, using good fuel etc.This is not a recent problem. I'm inclined to agree that it may be a cumuation of things being off which is causing the problem. We'll see.
 
#19 ·
Re: idle speed problem at start up

I bet that lumpiness is caused by bad plugs. In fact, I wouldn't be surprised if you found the entire situation greatly improved by just replacing the plugs.
 
#21 ·
Re: idle speed problem at start up

Starter valves?..... and ya it will want to stall unless you help her for just a sec or two....especially when its cold. You said that it is acting weird until 120 F....so take a video of it cold and upload it....The idle should settle down around 107 F....
 
#22 ·
Re: idle speed problem at start up

Prob needs new stator, reg, battery, plugs, valve adj. , air filter, CCT, cam pulse gen. , ignition pulse gen......that's what I would do...If you were closer I could help ya out for a lot less coin then a dealer....
 
#23 ·
Re: idle speed problem at start up

Prob needs new stator, reg, battery, plugs, valve adj. , air filter, CCT, cam pulse gen. , ignition pulse gen......that's what I would do...If you were closer I could help ya out for a lot less coin then a dealer....
Man, it would be nice to have a mechanically inclined Bird guy near me. Anyway, thanks for the thought. Fly out to sunny CA, work on your suntan and I'll put you up, wine and dine you ?CCT, battery, air filter replaced recently. Think the stator and reg/rec are fine. Battery has always held a charge and had a meter on it about a year ago where it showed the charging system working correctly.Plugs, valve adjust, TB sync for sure. Not sure about the cam pulse gen and ignition pulse gen. Do these go bad after a while?Good idea on the video. Will post tomorrow.
 
#24 ·
Re: idle speed problem at start up

Hi ,I am new to this forum and I don't know this bikes at all...I actually swapped my boat for this bike...2003 Blackbird ,I've got the same problem as you described...what is a Wax and is it sorted???
 
#25 ·
Re: idle speed problem at start up

I had some start problems and also problems with the idle speed. There was some water in my fuel tank. Parked the bike at a bikers meeting and there comes a very big rain shower. Than the problems began. Made the tank empty and also the fuel rail. New fuel and the bike runs perfect.


Jan