Hey everyone, this is my first post. I just got my bike, its a 2000 cbr 600 f4. I love it so far, but one problem is after a bit of riding, once the bike rides for a bit (about an hour), I get an idling problem. The bike will be a bit hesitant until about 3000 rpm and then it drives fine. The temperature is normal, and I had the battery changed not too long ago. Im currently running 89 octane, i used to run 91 but i thought it would go away with a lower octane. Anyways I think its something electrical, i dont think its anything to do with the carbs, as it would be like that when its cold as well. Anyways do you guys have any ideas what it may be??? Thanks
Mike

 

Once your bike starts having the idling problem what will make it go away? Can you turn off the bike, and when you turn it back on (right away) will it go away? Or do you have to wait until the bike cools off before it goes away?

 

would lowering the octane do anything??? i thought raising it was better for the bike.

 

Hey mikey1011,

I was looking on the forum for a problem that I am having, which is identical to what you are describing...everything OK when the engine is cold, but after it is hot rough idling in traffic or at a red light and the engine dies. I also have the same model year bike (i.e. 2000 CBR600F4).

This is a really dangerous problem, because the bike usually stalls when idling at a red light. And then when you start to drive off, it will hesitate while accelerating...if it dies now, you'll be lucky if the car behind you doesn't ram into your rearside!!

I have temporarily got around this problem by increasing the idle speed to 3000 rpm (Honda manual recommends 1300 rpm -/+ 100 rpm). This is really bad for the engine though!!

What is the mileage on your bike? Mine is around 25000 km. I am just wondering if it is a feature of the Honda engine if no work has been done on it...perhaps the carburetor adjustment goes "out-of-whack" after certain time/mileage. (I know that I haven't had any carb adjustments done on the bike over the last 3 years.)

I sort of disagree when you said "i don't think its anything to do with the carbs, as it would be like that when its cold as well". The reason being that at higher temperature, the fuel mixture entering the carburetors is leaner (because the gasoline will vapourize/evaporate at higher temperature i.e. when the engine is warm). So, unless the carburetors are adjusted to deal with the incoming fuel over a wide range of temperature, the engine will have problems idling at low rpms.

The owner's manual talks about "high altitude adjustment" of the carburetors, and the symptoms for riding with badly-adjusted carbs are the same as the problems we are experiencing, i.e. rough idling at low rpms.

I haven't approached a motorcycle technician yet (I live near Toronto, Canada) but I will soon...I just want to be certain about what I am getting into in terms of cost and labour before they "take me and my wallet for a ride", without fixing the problem. I don't have the necessary tools and equipment to do a carburetor synchronization on my own, so I think my best bet would be to take it to the Honda dealer and have them look at it. It will probably cost a few hundred $, but I think they guarantee the work, so if the problem re-occurs they should fix it without additional cost (in theory).

Does anyone have any more insight into this problem?

Thanks,

 

Start with the battery and check the voltage. Check if you have good connection throughout the charging system of the bike meaning your getting voltage back to the battery >13.0v when you rev it up to 5000rpms. Does your bike cut off when it's hot and the fan has kicked on? When you changed the battery, you did all the charging prior to installing it to the bike right.

When this happened to me last year, the problem was my battery all the way down to the alternator. Had to change everything but the wiring. Now with aftermarket charging system it puts a greater charge back to the battery. Changed the fuse and I also changed the coolant which keeps the temp down. Luckly I didn't have to go into the fuel and carbs.

But carb synchactually easy to do if you have the materials to do it. A decent carb synch cost 50 - 60 bucks but the pilot screw driver is about 100. I do the work myself with a little help from friends and family. However, I'm not a motorcyle mechanic by profession and I did want to know how much a tune up would be at Honda service and they were going to charge me 360 - 420. I asked what they do and basically carb synch, battery charge, and I think a valve inspection. This is Cali prices.

As far as octane, I use 91 which is the highest here. Burns hotter and cleaner is what they say. But someone told me that it's all about good plugs, fuel mixture is tuned, carbs are synched, and air filter clean to make this work. Bikes are high rev engine therefore require quality gas. It's actually good for the engine to rev high (not redline) once in a while (if you're the conservative type) to clean out some of the deposits.

Well I guess that's my 2 cents plus tax.

 

Hey guys, thanks for all the replys, as far as charging the battery i took it to a shop. The problem goes away once I stop the bike and it cools off. Could it be the thermostat??? I have to replace mine because its stuck up, or is it possible that it doesnt have good circulation?. Anyways i took it to the same guy who changed the he said that the carbs are out of sync. Problem with that is that sometimes i have absolutely no problem with it.If it would be the carbs I would think it would be reoccuring all the time. Anyways I think i will just let them sync the carbs and change the thermostat. I know cars but I dont really know bikes yet. The bike has 57000 km .
mike

 

Hey guys, a quick note on the Octane topic, the higher the Octane rating of the fuel the better. In the UK we have 95 and 97, I'm currently running 97 after making a switch and the higher Octane rate fuel does run far smoother and is far better for the engine. Also in manuals for bikes it tells you to run a higher quality fuel (higher Octane) as it's better for the bike, it also helps the bike to perform better too. Fuels with a higher Octane rating burn more efficiently, so the higher the rating the better. However I've also heard that there's a point at which you can go too high with the Octane rating, but you'll have to read more into that cause I've had a few drinks, so Wiki's probably your best bet for reading up on this at the minute lol. But with the stuff available to us from the pumps with regards to Octane ratingsthe higher the better out of the 89, 91, 95, 97 Octane fuels.

 

yes yes octane is very important ,here in cali we have 100 octane at the pump and what a diff. it makes,runs smoother and smells better too

 

by buying lower octane youre doing your engine and your wallet a disservice.
the few cents more for higher grade fuel are because theres MORE fuel in it!
it lets out more energy per weight when it explodes.
we can only get like 93 or 95 here now. but my friend said he rides out to the airport to fill up on 103 or some-such jet fuel.

charging issues make sense at idle. youd be fine at speed right?
but then why would it be fine restarted right away? wouldnt it die more when you tried to start it back up? i dunno enough to help. good luck.
ill be watching . i hope it doesnt show up on my 99 600

 

I know this is off topic, but where I live, I've only seen 91 or 93 octane. What gas stations usually have higher octane?
And what about octane "boosters"? do they actually work? ....and how exactly?