Re: Karizma/Karizma R

We have installed piston rings/bore twice before and there was no problem. This is the first time. Correct diagnosis can be done only when I open the engine. Sibun and Shoeb are in extensive discussion about this, and lets see what they say. Most probably I would get new piston rings and install. I have run only 160 kms after the new bore kit, and I hope there are no scratches on bore and piston.

Re: Karizma/Karizma R

[MENTION=11210]ravi@17bhp[/MENTION] - I have already told in the first post itself that while fitting new bore check the rings gap and if it is more then just use 0.25 size rings by grinding properly as i have explained.

The problem is that in case of new bore kit usually there are different vendors for rings, bore and pistons. Each are also having tolerance value in +/- as recommended. When company is assembling the engine then rings are checked against bore and fitted with matching tolerance. But in replacement bore kit it is packed by machines. What happens is that machines just reads the tag and picks up the packets and pack them in a single kit. It doesn't matter what the tolerance is. as long as the part number matches it packs them.

That is the difference between man and machines as man can check and pack as to whose tolerance matches with whom. This is not a problem with Hero but all other companies. That is the reason why some companies are giving bore, piston and rings all in different packings so that while fitting one can check and fit.

For now take it to [MENTION=14414]shoeb[/MENTION] and not to anyone else. I have explained him in details over phone on what to do and he can make you understand practically. I have done these all and have also seized my Joy's engine once due to piston problem.
[MENTION=52772]AK3D[/MENTION]- You are right on machine polishing eating up the valve seats and also uneven polishing but i would like to add here that compare a hand polished valve and machine polished valves and you can see my point there. The smoothness of hand polishing can never be done on machine as they rotate a lot faster.

Regarding piston getting scratched, then nothing to worry as it will be the skirt region and anyway that will get scratch and nothing to worry. I have personally seen new rings in new bores to have large gap which causes bike to smoke and eat oil. I have used 0.25 size ring by grinding and bike has run for 60-70k before needing ring change. Even my mechanic has done the same on many bikes be it splendor, karizma or pulsar, and all bike have run excellent without consuming oil.


Open any new bike bore and you will see that rings will be having hardly any gap,

Re: Karizma/Karizma R

@sibun, thanks for the inputs. I have checked the ring end gap before installing. Its ~0.15mm, which is within standard limits per CRF230 service manual. Even the piston rings on my old bore had the same ring end gap and it has worked well with good compression (160 psi) and with no visible smoke. I have changed the bore unknowing that the problem is with Carb.

Shoeb asked me about tapering ends of the piston rings and asked me if I checked them before installation. I didn't know about this, and the only thing i know is that there are marks on piston rings and those marks should be on top side. I don't know if there is any procedure to check for taper ends of the rings, other than looking for the marks on the rings. I would ask Shoeb details about this.

Regarding the machine picking, this is a serious issue that Hero should look into. Bore kit is vital for the bike, and if the company just says machine picking and its machine fault, thats not acceptable. The amount of trouble customers have to face due to this problem is unimaginable. It proves very costly for the customers.

Also, I am puzzled as to why there are variations of standards with different vendors. The manufacturer should ensure the vendor makes the parts with standards required by the manufacturer and not by the standards of the Vendor.

Anyway, I would speak to Shoeb and see what can be done. Also, need to make sure if the rings are properly installed. Once again, thanks for your valuable inputs.

I am posting the CRF230 manual about the piston rings for reference.

Re: Karizma/Karizma R

Ideally this should not happen since you've been so careful with the entire installation, however things that can go wrong will go wrong. I know it's a frustrating time for you, but I'm glad you're taking this as a learning experience also. Good luck sorting everything out soon Ravi.

Re: Karizma/Karizma R

Hey guys, I came across the information on the NGK Plug, thought of sharing with you all here.




If this info already posted before, please feel free to have Moderator to remove it.

Re: Karizma/Karizma R

Thanks Sriram for the chart. Its really helpful, at least to me.


My previous LEDs, 6500k, 275 rupees, 1W each.




New LEDs, 5000k, 650 rupees, 3W each, aluminium heat sink, high quality.




The petal/floral reflections are clearly visible as the LEDs are there on four sides. If you take bulbs with LEDs only at the front, these floral reflections won't glow.

Re: Karizma/Karizma R

Firstly I am no expert in this , but is it possible that the oil leak has been contained and the remnants of the oil that had leaked earlier is now appearing as smoke as it vaporises from the exhaust system heat ? Then you can run the bike like it is now and keep checks as you go along . nahi ? oil level is stable now ?

Re: Karizma/Karizma R

For oil, there won't be any remnants for days. Once you ride the bike, it will be burnt completely. Moreover, there is less compression too than normal. This, along with exhaust smoke, definitely confirms the oil leak. We have to open the engine and diagnose the exact cause. With compression test, its certain that piston rings are leaking. There may be other issues like gasket leak too.

Re: Karizma/Karizma R

The issue has been sorted out with new batches of bore kit. I think you got from old batch bore kit. But the thing is that it is not a problem but we must check them before installation.

Grinding and fitting is the best as it gives good bore sealing and runs longer than new rings in kit and oil consumption will be nil. My mechanic and i even though rings gap will be ok but at the least we will fit oil rings one size higher than std by grinding.

Regarding that service manual then let me add here service manual says something but pratical is something else. Ask shoeb when his splendor was misfiring and he checked the resistance of excitor coil and it was within specification of service manual. He asked me that when the engine gets hot the resistance changes and then he changed the excitor and it runs good.

You see by studying the service manual we cannot be expert. Always experience teaches and experience is the best teacher.

I know you are frustated but let me add here that this will ultimately teach you more about bike. When my Joy had a carb defect i re-build the engine and what not, took me one year for locking on to carburettor.

Since my fathers splendor was under warranty i didn't dare to swap carburettor and check.Waited till the say it turned one year, the next day itself took both the bikes to mechanic and swapped complete with intake manifold. One kick and i knew that it was the solution.

Next day itself bought the carb from my retailer friend, cost was Rs.1700 but since he is my friend gave me a discount of 10%(screw hero goodlife card as i get more discounts from my friend). More than two years after changing bike is running like crazy.


So you see since i had faced the problem i could help you to pin-point the problem. So do not take this as a set back but take the help of shoeb and get to learn something that will help for your next time.

Open the bore check the rings and get 0.25 size rings from shops that sell piston, get USHA or GOETZE rings and rest i have instructed to shoeb over phone.

Re: Karizma/Karizma R

[MENTION=6275]Ravi[/MENTION]...The new bore and Piston have to wear and settle down. You had measured the new rings gap inside the nw bore and found it to be 0.15 which is within spec. It is the oil burning which needs to be addressed , along with lean AF metering in the Carburetor.
Good luck.

Re: Karizma/Karizma R

That's so true. Just like there is no replacement for displacement, there is no replacement for experience.

We had planned to get the work today but just now I called few retailers and all of them are closed. So maybe tomorrow we will get the work done.

Thanks for your prompt support as usual.

Re: Karizma/Karizma R

UPDATE: Fourth day morning, started the bike with choke on. For the first 30 seconds no visible smoke from exhaust. After 30 seconds, slight smoke started coming out and it waned off after 10 seconds. I am posting the video below.



@sibun, I agree that experience scores over specifications. Like you, I have built my engine twice for the carburetor problem. Of course, its a great learning experience for me.

@shoeb2015, check the video above.

Is there any possibility of leaking gasket, getting sealed with burnt oil slowly? Just a thought. First day no smoke, second day considerable smoke, third day little smoke, and four the day very little. Any other interpretations here?

Re: Karizma/Karizma R

Today there was lot of confusion.

1.When I and my mechanic took a test ride, there was a distinct crank noise at 5k RPM under acceleration.
There was no doubt that the crank had to be replaced but the confusion was WHEN to replace it ?

2.We replaced the air-screw but even then, tuning the carburetor was very difficult. Still that idling issue and harshness was there. Mechanic had to adjust it several times.
The confusion was that there were two kinds of knocking one due to improper mixture and the other due to crank. Ravi will be swapping a carburetor and test the bike for whole day.

3. Compression increased slightly to about 10.3 bars indicating that rings were sealing better after each and every passing kilometer.
Sibun asked us to go for oversized rings after grinding them but my mechanic was against it.
PSR sir asked us to wait for few hundred kilometers, even my mechanic had the same opinion.
My opinion was that if these rings are not sealing now, it may set bed-in properly after few hundred kms but then it will lose compression again after after 10-20K kms.

The confusion was if it was the right time to remove the engine open the head and inspect ring gap along with dowel pin and head gasket for any leak ? For now, sibun has suggested to use a heavier oil ie. a 15W50 mineral oil.

4. We had three problems at hand 1.crank 2. rings 3. carburetor.

If we wanted a permanent solution NOW then all the three would need replacement and it would be very-very heavy on the pocket. But if we continued the same way then the bore will be damaged and would add to the cost later. My main concern apart from the smoke issue was to save this new bore.

We came to a conclusion that if the smoking issue gets solved after run-in then we won't open the engine and Ravi would continue to use it till the bore gets damaged(around 30,000kms) without any tension, freely.

I and Ravi returned back to our homes with a lot of confusion in mind.

Lets see what happens.

Re: Karizma/Karizma R

UPDATE: All confusion!

But, of all the problems/issues that Shoeb mentioned above, the main issue is the exhaust smoke. Else, the bike is very much fine to ride. The crank noise was very little only and we can ignore for now. The low gear/low rpm knocking is also not a serious issue and I can continue riding/touring. So, the exhaust smoke in the morning is the one that we have to look into and address it immediately. I brought this issue upon me by myself. I shouldn't have changed the bore in first place. We checked the old bore today thoroughly and we find it to be fine. With compression around 11, the old bore would have run for at least 40k kms.


UPDATE ON EXHAUST SMOKE TODAY: Started the bike on choke and noticed the smoke coming out earlier than yesterday (after 33 seconds) at around 15 seconds. The intensity of smoke is slightly more than yesterday. Its all puzzling as to why the smoke is coming only after some time and not when the bike is started. Will update this post with the video soon.

Also, yesterday removed the carb to put the washer to raise the slide needle a bit to allow more fuel. This washer that I intended to use was the aluminium washer that comes with AFR screw. As I still have the old AFR screw, I took it out to use the washer. Just like that, I did a comparison and found out that the O ring on the current AFR screw is hard like a plastic, and the O ring of old AFR to be rubbery. I suspected this O ring to be the culprit for the unstable idle and replaced the hard ring with the rubber ring. I immediately noticed improved idling (may be psychological ). Thought I had solved the idling issue, but it was not. Today when I rode, everything was like before, and I still have the unstable idle.

Re: Karizma/Karizma R

Ravi, try replacing the pilot jet to attempt a solution to your engine's uneven idling. Chances are the issue will disappear. Ensure you get the right part number though.

If you can't find a replacement pilot jet, then attempt to clean it thoroughly.