Re: Honda CBR 250R

I've got a bit of a confusion. I've seen a few people here saying this.
"Open the throttle along with self start to start a flooded engine."
Can someone give some insight into this? As far as I know, engine flooding is basically the case when there is too much fuel in the combustion chamber. This is usually caused when you hit the starter with the throttle being open for too long.
So if you already have a flooded engine, how does opening up the throttle and gunning the engine help?

Please correct me if I said anything wrong in there.

Re: Honda CBR 250R

In an FI engine, when you open the throttle wide open the, FI unit sends a message to the ECU to halt fuel spray to injectors. So, what happens when you basically crank the engine with WOT, the engine just spins and sucks in air (without fuel) so with this cranking happening, and the air coming in, the excess fuel inside the cylinder is pushed out of the combustion chamber. So basically it's like clearing ones sore throat by gnarling and then spitting out. It's clearly stated in the manual to do the same if the bike gets flooded, meaning if she just keeps cranking but doesn't fire.

It is 2.5 according to the Japanese manual. Theoretically, it can be plus or minus a few 100 ML.



Cheers!
VJ

Re: Honda CBR 250R

Oh alright. Thank you!

Re: Honda CBR 250R

Loved the narration!

Just wanted to know a bit more on the same topic, i.e. how does the engine gets flooded? I mean as per your explanation somehow the flooded engine caused by excess fuel and that's get cleared with air pressure while cranking with throttle opened. So how does this over spray of fuel happens inside combustion chamber? Is it a random fault of the ECU or something else?

Re: Honda CBR 250R

You know that the ECU primes the engine on start up, right? What that does is basically spray fuel into your engine and also performs an auto-choke function. As you know, during a choke, the engine is rich and running at a higher idle RPM than normal. This is done to ensure the start of a cold engine. Rightly as you guessed, it's a random ECU error, as well as human error sometimes. If you keep turning on the ignition and turning it off without moving the bike, you'll make your engine too rich, shutting it off and making it hard to start. That's as far as my knowledge goes.

Re: Honda CBR 250R

It is 2.5 according to the Japanese manual. Theoretically, it can be plus or minus a few 100 ML.



Cheers!
VJ [/QUOTE]

Just for a check, once I rode it till the fuel tank emptied. From the point when last bar starts blinking I managed to rode it for 100km. I was riding at 40-60kmph in mountains.

Mostly I fill fuel when last bar starts blinking and it gets 9.5L to fill it till the neck. I guess 300ml more could go if some time is given to settle down the fuel. So as per this calculation, I would say it is close to 3.2L

Re: Honda CBR 250R

I had got the chain adjusted around 1.4k km ago. After how many km should the chain be adjusted ? Or what are the symptoms that tells us that the chain is loose

Re: Honda CBR 250R

[/QUOTE]

Yes, even I rode almost 80kms on last bar blinking prior filling it up. In last 4 years I didn't have a signal ignition failure apart from some rare flooding. But this time with blinking last bar, the bike is not starting at all. Battery is fine as I checked the headlights and those are working perfectly fine.

Honda CBR 250R

This very similar thing happened to me last month when i came back after 15 days. As usual i cleaned the bike in morning only and cranked it up (this is the first thing i do when I return after an outing without my bike).

It instantly fired up and then very next moment there was a (BHUPPP) sound of failed ignition from inside the combustion chamber and it stalled.
Just as always I tried cranking it up with throttle open ( this is a common problem with my bike and happens once or twice in a month). But this time it simply refused to start.
I tried turning on off ignition several times. Nothing helped!

Since the fuel was at last bar I tried tilting bike the old school way and cranking. Still no sign of life

Since there is no good mechanic near me for handling my bike i went on stubborn mode and cranked the engine continuously for at least 25 seconds with half the throttle open and it fired up with some hiccups and instantly rose to 5k rpm since throttle was open.
Although i noticed some very light grey smoke from exhaust when it started

I kept it in that condition for around 10 seconds and then dropped the throttle and everything was back to normal. No more smoke or anything suspicious thing

And later on i went for a short spin. Everything was fine

So if nothing helps i would suggest you to try cranking for a little bit longer with half the throttle open. It might help you too

Re: Honda CBR 250R

I don't know exactly how many kilometres between chain care, but as far as I've deduced from a lot of research - do it as much as necessary. Check the chain slack every week and once it's past permissible levels, tighten the chain. Loose chains cause a lot of palpable losses in performance - principally you may find that your bike doesn't respond as sharply to throttle inputs as it used to, you gear shifts will become notchy and your gears will start dropping or you will get a lot of false neutrals and lastly the chain will make a lot of noise as it has a hard time getting onto your sprocket. These are the tell tale signs of high/low chain slack.

Re: Honda CBR 250R

Yep, I've ridden on last bar blinking for 70-80 kms. No way it's possible with just 2.5L in single bar mode. Also filling soon after last bar arrives, I can put in only 10,10.5L max.

So I assume the online manual is wrong, or else the 'reserve' is set to 3.5L in the Indian CBR, and 2.5L in the jap one

Re: Honda CBR 250R

A few days back I faced this unusual issue of radiator fan running even after ignition key and engine kill switch was turned off. I was cruising on highway at 80kmph in 6th gear(fan shouldn't be running in this condition). As I stopped by a fuel station I observed that fan was running. I turned ignition key off and it was still running. I waited for 5 minutes but it kept running. Later when I reached my place, I took out the fan relay fuse(10A fuse in fuse box) to turn the fan off.

Next morning when I put fuse back, fan started running. I thought it might be a fault with the relay, so I thought of taking it out for testing it with multimeter(I took out the relay fuse first). I tried but it didn't come out with plier. meanwhile I inserted back the fuse. This time fan didn't run. I took the bike out in traffic to check for functioning of fan.

It worked fine. After riding for sometime in traffic, fan kicked in. As I switched the ignition off, fun also stoppped. Few seconds later I turned the ignition on and the fan kicked in again. I think this is how the fan is supposed to work.

What I can make out from all this is that problem might be with relay. There are four contacts in relay out of which two are for energising the coil and out of other two, one is normally open(N/O) and the other is normally closed(N/C) contact. Normally the armature is connected to N/C(Fan circuit is not complete). As the relay gets signal from temperature sensor/ECU the armature moves and makes connection with N/O, which completes the fan circuitry.
These are links to understand the working of relay.





What would have happened in my case was that the fan turned on when I was stuck in traffic(20km before I observed the fan running) and the armature stucked to N/O contact. Later in my failed attempt of taking out the relay, armature moved back to the N/C contact.

PS: My explanation could be wrong. I just tried to correlate my observations. Any leads in explaining the possible cause and solution is welcome.

Re: Honda CBR 250R

Does a worn out ball bearing set really affect handling? Took my bike to the svc , found I have a bent fork, handle bar , t stem, bent top plate, a leak in the front rim, I guess I got used to the handling but lately it's become worse , will be leaving at the svc on Monday to sort out n see what's the issue, was quoted around 3500 , with fork bent removal and cone set change , if top plate n handle bar need to be changed I expect a 8-10k bill.

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Re: Honda CBR 250R

Thanks a ton. Your method actually worked. So this evening I poured 2lt of fuel into tank so 4.5lt was in tank. Even after that engine was not able to start. It behaves same as before. Then I kept holding the throttle and self for about 30 seconds and it came back to life. One or twice it died while I turned the pilot lights on but eventually after few minutes of idling even that was working good. My battery is due for a check but I believe it's not a battery problem, as I was able to turn on all the lights even when the engine wasn't cranking.

Re: Honda CBR 250R

Your welcome buddy. I am glad that it helped in your case too.
But i don't think it's something related to battery because I checked my battery using multimeter and it seemed normal.
It might be something related to earthing or probably our FIs going nuts. Just a guess from my side.
Well, only our gurus here can throw some light on this issue