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**Siddhanth Paul** · 03-11-2020, 10:14 PM

Re: Honda CBR 250R

Any specific reason for glazing with sandpaper?

Originally posted by B7ACKTHORN View Post

Yes, they are a direct swap for the rear. Secondly, before installation make sure, the Pulsar pads are glazed mildly with sandpaper and then installed.

Cheers!
VJ

**B7ACKTHORN** · 03-11-2020, 10:50 PM

Re: Honda CBR 250R

Originally posted by Siddhanth Paul View Post

Any specific reason for glazing with sandpaper?

Helps clean the glazed surface and brings the fresh pad material in contact with the rotor soon and prevents glazing.

Cheers!
VJ

**arvstreetracer** · 03-12-2020, 12:08 AM

Re: Honda CBR 250R

Originally posted by cbr250abs View Post

Hey guys

I'm planning to get a metal piece welded under the side stand rest to raise its height ( 5mm to 1 cm ) to address the issue of too much side tilt and broaden the base of side stand rest a bit of my cbr.

Is there any chance of it messing up the bike electronics or any other stuff in the bike?

I have done so but without welding - drilled two holes at the base of stand and fixed a 6 mm thick plate. Try to curve it before fixing. Just make sure to align the plate in way that it won't touch the chain when stand is off. You may remove it whenever you want.
Pics for your reference.

**arvstreetracer** · 03-12-2020, 01:01 AM

Re: Honda CBR 250R

Originally posted by mitz View Post

approximately 3000 for service and parts seperately. Let me know if you need the cost of any specific part, I'll try to get it from one of the invoices.

So friends, it's been almost a week since I'm unable to find a spark plug cap in Mumbai. Since I did not want my bike to be lying around at the FNG garage for such a long time, on my insistence the FNG mech did a local jugaad of fitting a KTM spark plug after some modifications. (I know this was a bad risk) He also adjusted the idle RPM to address my stalling issue at idle RPM, though the FNG mechanic says there was an electrical short on the throttle body which was causing the erratic RPM which is fixed now.

Well, the bike worked well for whole of 20 kms and now I my RPM idles at 3k rpm. Now I'm just waiting for the spark plug cap to arrive post which I'll have a thorough check done at Official Honda SVC

Has any one tried manually adjusting the rpm on throttle body?

I have fiddled once with that butterfly valve stopper screw. Needs a lot of patience and time. Requires 7mm open end wrench and a 3 or 2 mm Allen key. You can slightly raise or down your rpm - there isn't much room to fiddle with that. I raised rpm till 1700 and rode for a day. Later set that to 1500 rpm. All this happened with a slight turn of that screw. At factory set screw, butterfly valve shuts completely and then IACV stepper motor plays the role. What happens when you tight that screw, it opens butterfly valve and let the more air in than the desired amount along with IACV bypass route (as stepper motor lifts the IAC valve at idle) which gives a sudden raise in rpm up to 3k or more. It's like fine tuning a carburetor. In your case, you need to rotate it anticlockwise - hardly a 1/4 turn or so and then tight the bolt. Before doing so, cover the engine area beneath throttle body to avoid losing allen key into the gap between starter motor and cylinder. I ended up searching that key with a magnet

...

**cbr250abs** · 03-12-2020, 10:54 AM

Re: Honda CBR 250R

Originally posted by arvstreetracer View Post

I have done so but without welding - drilled two holes at the base of stand and fixed a 6 mm thick plate. Try to curve it before fixing. Just make sure to align the plate in way that it won't touch the chain when stand is off. You may remove it whenever you want.
Pics for your reference.

Thanks, this is brilliant idea. May be I would buy a new side stand ( which is ~Rs 100 ), get the work done ( drilling and stuff ) on it and swap the side stand.

**mitz** · 03-13-2020, 03:32 PM

Re: Honda CBR 250R

Originally posted by arvstreetracer View Post

I have fiddled once with that butterfly valve stopper screw. Needs a lot of patience and time. Requires 7mm open end wrench and a 3 or 2 mm Allen key. You can slightly raise or down your rpm - there isn't much room to fiddle with that. I raised rpm till 1700 and rode for a day. Later set that to 1500 rpm. All this happened with a slight turn of that screw. At factory set screw, butterfly valve shuts completely and then IACV stepper motor plays the role. What happens when you tight that screw, it opens butterfly valve and let the more air in than the desired amount along with IACV bypass route (as stepper motor lifts the IAC valve at idle) which gives a sudden raise in rpm up to 3k or more. It's like fine tuning a carburetor. In your case, you need to rotate it anticlockwise - hardly a 1/4 turn or so and then tight the bolt. Before doing so, cover the engine area beneath throttle body to avoid losing allen key into the gap between starter motor and cylinder. I ended up searching that key with a magnet

...

Thanks for sharing your experience. I'm not much for DIYs but will keep an eye out when I get this done from the FNG Mechanic. I do check the idling rpm everyday and it is keeps fluctuating between 2-3 k rpm, probably due to reasons you explained above. But I wonder if the non-OEM spark plug cap may be causing some interference in any way as my Mechanic claims that it is probably heating up the engine which is increasing the RPM.

For now, I'm still awaiting the OEM spark plug cap to get this sorted out at once.

**Deathwing** · 03-16-2020, 11:07 AM

Re: Honda CBR 250R

I have raised my rpm limiter to 11000rpm plus , bike was idling at 2500-3000 because of the after market ecu , but adjusted it now at 1450-1500 range which is ideal idling I'd say .

Originally posted by mitz View Post

Thanks for sharing your experience. I'm not much for DIYs but will keep an eye out when I get this done from the FNG Mechanic. I do check the idling rpm everyday and it is keeps fluctuating between 2-3 k rpm, probably due to reasons you explained above. But I wonder if the non-OEM spark plug cap may be causing some interference in any way as my Mechanic claims that it is probably heating up the engine which is increasing the RPM.

For now, I'm still awaiting the OEM spark plug cap to get this sorted out at once.

**The Pain** · 03-16-2020, 11:28 AM

Re: Honda CBR 250R

Originally posted by New guy View Post

My bikes done over 63k kms and had lost power and FE over some time.
SVC opened the head and says I need a new piston kit. Some pics attached.

My question is will it be ok with just the piston and liner or do I need the block too like the svc insists?[ATTACH]253427[/ATTACH][ATTACH]253428[/ATTACH][ATTACH]253429[/ATTACH]

What are the costs involved if you can share. Thanks

**New guy** · 03-16-2020, 11:51 AM

Re: Honda CBR 250R

Originally posted by The Pain View Post

What are the costs involved if you can share. Thanks

I have been quotes 10k for parts for piston block kit, exclusive of labour.

**arvstreetracer** · 03-16-2020, 11:55 AM

Re: Honda CBR 250R

Originally posted by New guy View Post

I have been quotes 10k for parts for piston block kit, exclusive of labour.

Are the valves okay? It's good to get them inspected first before changing cylinder and piston. Check for burnt valve/too tight valve clearances.

**New guy** · 03-16-2020, 12:07 PM

Re: Honda CBR 250R

Originally posted by arvstreetracer View Post

Are the valves okay? It's good to get them inspected first before changing cylinder and piston. Check for burnt valve/too tight valve clearances.

Valve seat is also been chkd. Mostly will have to do reseating. Guides are ok.

Shim clearance is also off.

**arvstreetracer** · 03-16-2020, 12:28 PM

Re: Honda CBR 250R

Originally posted by New guy View Post

Valve seat is also been chkd. Mostly will have to do reseating. Guides are ok.

Shim clearance is also off.

Then most probably it was compression leak due to burnt valve/s. I doubt you need a cylinder kit this time. Tight clearances result in burnt valve over time and thus compression leak. Loss of power, hard cold start, noticeable drop in FE, and stalling are few symptoms. Valve guides have nothing to do with compression leak - if worn out, they make noise.

**New guy** · 03-16-2020, 12:32 PM

Re: Honda CBR 250R

Originally posted by arvstreetracer View Post

Then most probably it was compression leak due to burnt valve/s. I doubt you need a cylinder kit this time. Tight clearances result in burnt valve over time and thus compression leak. Loss of power, hard cold start, noticeable drop in FE, and stalling are few symptoms. Valve guides have nothing to do with compression leak - if worn out, they make noise.

This is the state of the parts. Seems have reached end of life.

**arvstreetracer** · 03-16-2020, 12:39 PM

Re: Honda CBR 250R

Originally posted by New guy View Post

This is the state of the parts. Seems have reached end of life.

May be. It's hard to guess by seeing this photo. Can you click clear pics of inner walls of cylinder? There are visible dull marks in center, but I don't see any scoring or change in shape of inner wall.

**New guy** · 03-16-2020, 12:53 PM

Re: Honda CBR 250R

Originally posted by arvstreetracer View Post

May be. It's hard to guess by seeing this photo. Can you click clear pics of inner walls of cylinder? There are visible dull marks in center, but I don't see any scoring or change in shape of inner wall.

The piston is in a bad shape though.

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