Re: Honda CBR 250R

The handle makes a thud kind of sound on sudden potholes and spead breakers.Also when I just stop the bike try to push the handle up and down with the front brakes applied a small sound comes.

Re: Honda CBR 250R

Oh my, I have the same issue for the past 26,000 kms. My handlebar hasn't fallen off though. So I haven't bothered to change the coneset. I must be one uncouth, uncaring lout, running a CBR without coneset change at 46k. [emoji16]

Re: Honda CBR 250R

I am also trying to find a cure for spark knock for last 30k km, but all in vain. From changing oil to ECU reset, everything tried but this spark knock occasionally jumps off when riding in hot condition, going uphill, with pillion etc. Now I have changed my riding style and do not give it any chance to happen. In my current ongoing therapy, I am adding System G for last refill in hope to get rid of any carbon deposits which trigger the uneven sparks. It doesn't​ happen when I use BP97 petrol. There may be multiple reasons behind it.

Re: Honda CBR 250R

Is there any issue of timing chain in cbr,that the chain comes out of the cam itself?

Re: Honda CBR 250R

Is it the sound which I do get while pushing the bike in higher gears? i.e. I get a metal knocking sound from engine whenever shifting to 5th or 6th gear on RPM band 4000-5000 and accelerate from there. I am living with it from last 10-15k kms.

Re: Honda CBR 250R

Hey guys, whenever I hop on the bike, the front sags down a bit. Suspecting front fork springs are worn. Am I right?

Re: Honda CBR 250R

Yes, the same. Avoid it. Not good for piston and its surroundings.

Re: Honda CBR 250R

I think I'll give you some company there.

Cheers
Ride Safe
Krishna

Re: Honda CBR 250R

Guys I'm facing some ignition issue. The bike is making a krrrrrr sound near the battery when I try to crank the bike. The stator coil and charger was changed last year. I installed the new battery last year too.
I've got the battery charged today, and I've cleaned the fuses with WD40.
Any ideas what might've gone wrong?

Re: Honda CBR 250R

When was the last time your changed your fork oil? CBR riders know how saggy the front end is, primarily focused on ride quality. Over time, fork oil thins and sags even more. Replace your fork oil if necessary.


Extremely and highly unlikely. In case of such an event, where the chain is undone from the cam sprockets, the engine timing goes for a toss and we have catastrophic engine failure, and these chains are extremely robust, I have yet to come across a cam chain failure yet. Nonetheless, it's extremely unlikely for such an event to happen. But, as in mechanical world, anything can happen.

Check your starter relay underneath your front seat, protected by a 30 AMP fuse. Only a good charged battery can provide enough current to crank the engine, or for that matter spin the starter, though the console etc would fire up perfectly fine. If even after the battery is charged and you have that "kirrrrrr" sound, it's time to check your starter relay. Once the battery is charged, the bike should crank with a couple of cranks.

Keep your observations posted.

Cheers!
VJ

Re: Honda CBR 250R

Fork oil was changed last year, as one or the other fork oil seal have a tendency to give up every year.

Re: Honda CBR 250R

Less fork oil too means we have little to no compression or rebound damping. If you're the type who doesn't care for the speed breakers or just glide over them, then fork seals tend to have an early demise. Start off with fork oil and see how it fares. Using a thicker grade would help in reducing the front end dive, esp 20w as opposed to the stock 10w

Cheers!
VJ

Re: Honda CBR 250R

Finally the issue which was triggering the spark knock is identified and cured in my CBR. As I guessed earlier, it was carbon deposits which was working as hotspot under high temperature, load, going uphill etc.

I had cylinder head gasket leakage recently. A minimal amount of oil was seeping down the head near exhaust outlet - there is an oil passage lined through the cylinder on left side. Luckily, the gasket went kaput from outside and made the way for oil to seep out.


Check in above picture for exact location of seepage.

For that particular gasket replacement, you need to remove down the motor from chassis. Once the head was removed, I was surprised to see the amount of deposits over the piston in form of a thick crust.





This was what triggered the spark knock. IMO, when bike was new and there was no such carbon deposits, I didn't notice any knocking. But over the prolonged period of time all sorts of carbon and muck got deposited over piston and that triggered spark knock.

I cleaned all the deposits with the help of screwdriver and new gasket was installed. Rest of things were in good condition.






Camshafts were as good as new. No scoring mark anywhere. I have completed 50,000km.

Now the leak is stopped and best thing is that irritating spark knock is vanished!

Also, it seems Iftex system G works. Throttle body was clean and you can see the inlet side edge of piston which is a bit cleaner than the rest of it. It was 3 tank with System G in it.



I would like to know the opinion on System G from our our riders using here.

Re: Honda CBR 250R

[MENTION=29952]arvstreetracer[/MENTION] - the metal sound I face when accelerating from 4-5k rpm at 3rd or 4th gear uphill was in my bike at 10,000 kms onwards. Isn't that too early for carbon deposits to form?

Re: Honda CBR 250R

When first time I heard that knock, my odo reading was around 19xxx km. Since then it only increased... There are numerous reason for spark knock and building carbon deposit on piston or within combustion chamber is one of them.