Hero Hunk Technical Issues

[Dilshad969]

Hello there,
I am ridding HUNK since about 5 yrs. But lately I have faced a serious problem. The bike's engine started producing some sort of noise and the there comes out a lot of smoke from the exhaust. I took it to the mechanic and he told that the piston head and some other things (I don't remeber needs to be changed) and gave me an estimation of about Rs. 4000.
Kindly if anyone have knowledge about the stuff please help me. It's urgent.

 

[Mr.Boss]

Re: Problem faced o Hero Hunk

Smoke from a 4 Stroke engine is = oil being burnt inside the combustion chamber = transmission oil entering the chamber

Yes, what your mechanic said is correct. It may be due to worn out piston / rings or the valve assembly. To confirm this, check for the transmission oil quantity, it should be reducing. Price quoted seems normal (if it includes everything - engine rebuild + labour + oil, etc)

 

[Dilshad969]

Re: Problem faced o Hero Hunk

Smoke from a 4 Stroke engine is = oil being burnt inside the combustion chamber = transmission oil entering the chamber

Yes, what your mechanic said is correct. It may be due to worn out piston / rings or the valve assembly. To confirm this, check for the transmission oil quantity, it should be reducing. Price quoted seems normal (if it includes everything - engine rebuild + labour + oil, etc)

Thanks for the answer. I took it to the bike mechanic 1 hr ago. He opened the engine and said that your engine oil was over and you didn't checked it for this reason piston head is damaged which needs to change and
he said something about bore. He told for installing a new piston head boring will be done in the cyllinder (I think so).
Just one more question, does the boring thing need to be done? I fear that may effect the performance while after. Like the pick up and speed may decrease

 

[vishnu vichu]

Hello there,
I am ridding HUNK since about 5 yrs. But lately I have faced a serious problem. The bike's engine started producing some sort of noise and the there comes out a lot of smoke from the exhaust. I took it to the mechanic and he told that the piston head and some other things (I don't remeber needs to be changed) and gave me an estimation of about Rs. 4000.
Kindly if anyone have knowledge about the stuff please help me. It's urgent.

Many of my friends have faced the same issue with their hunk. Might be problem with vehicles produced in the same lot.

 

[Dilshad969]

Re: Problem faced o Hero Hunk

Many of my friends have faced the same issue with their hunk. Might be problem with vehicles produced in the same lot.

Sorry I will not say it's the problem with the bike. The problem arouse due my lack of attention.
The bike is 5yrs old. I have faced much less problems in it in compared to other bike that people I know have

 

[Mr.Boss]

Re: Problem faced o Hero Hunk

Many of my friends have faced the same issue with their hunk. Might be problem with vehicles produced in the same lot.

Not sure about this. But it is more to do with the maintenance, driving habit & vehicle age.

 

[Dilshad969]

Re: Problem faced o Hero Hunk

Not sure about this. But it is more to do with the maintenance, driving habit & vehicle age.

Do you have any suggestions for the fact that will the repairing as said by the mechanic will have any impact on bike performance

 

[Mr.Boss]

Re: Problem faced o Hero Hunk

does the boring thing need to be done? I fear that may effect the performance while after. Like the pick up and speed may decrease

Reboring is required and it will not affect the performance (if done by professional & professionally) By reboring the engine displacement will get increased (marginally) and this should help in increasing the performance as well at the cost of slight reduction in FE.

 

[vishnu vichu]

Re: Problem faced o Hero Hunk

Sorry I will not say it's the problem with the bike. The problem arouse due my lack of attention.
The bike is 5yrs old. I have faced much less problems in it in compared to other bike that people I know have

Not sure about this. But it is more to do with the maintenance, driving habit & vehicle age.

no, I'm not concluding that it is a problem. I just said that it might be one ,since i have experiences in my friend's frequently saying about the same issue.

I even have a friend whose piston was change twice while nearing 50 k kms. Every service was done on the authorized service centre itself and yet

 

[pravin1987]

Re: Problem faced o Hero Hunk

A rebore means replacin worn/damaged cylinder and fitting new oversize pistons and rings to restore original fit. Commonly +0.20" or 0.30" oversize.

reboot will result in marginal increase in acceleration as the bore size is increased from standard 149.2cc( as in case of hunk). I don't think top speed will change.

Proper changing of engine oil will ensure this problem do not occur.

I have a CBZ running at 75,000kms and karizma at 38,000. for cbz i always changed the engine oil every 3000kms. I don't rip the cbz, but on the zma engine oil is changed every 2000-2500 kms. I always rip the zma hard.

 

[Dilshad969]

Re: Problem faced o Hero Hunk

A rebore means replacin worn/damaged cylinder and fitting new oversize pistons and rings to restore original fit. Commonly +0.20" or 0.30" oversize.

reboot will result in marginal increase in acceleration as the bore size is increased from standard 149.2cc( as in case of hunk). I don't think top speed will change.

Should I go for bore or installing complete bore-piston replacement.. I am not getting to conclusion of what do?
Do you have any estimate of what it will cost on applying a new replacement?

 

[pravin1987]

It depends on for how long you are going use the bike. I would suggest a rebore..It depends on whether you get SAL pistons or usha kit. The SAL pistons were used in bikes like zma, cbz, hunk from 2008 to 2011 batches, this SAL pistons caused a lot of issues when rebored.

If your bike is from 2012( usha batch), you can safely go for reboring. If your bike falls under 2008 to 2011, then a complete replacement would be the better option.

I'm not sure about the cost, please cross check at the dealers and I would suggest the thing done from HMC service centre becuase you will have warranty.

THE WHOLE PROCESS:

just the piston replacement:

If you are just replacing the piston, then you need to first know the bore of the cylinder. This can be done by using a bore gauge to find the diameter or by reading the owner’s manual to find the bore specifications. Ultimately, the bore should be measured for the best possible results. After the diameter is known, then you can pick which size piston will work best in your cylinder.

reboring process:
If you want to rebore the cylinder- bore kit, then you will want to choose a piston of the OE bore size When you send the piston and cylinder for reboring, the machine shop(lathe) will match the cylinder bore to piston diameter.

the measurement differs a bit for cast iron block.

last time when i worked on my freind's pulsar 180 for reboring at 42,000kms. after reboring the bike has done 28,000 with a periodic maintainence.

how many kms your bike has done?

 

[Dilshad969]

My bike is from 2011 so this means it would not be better option to rebore it...rather I shoul go for a replacement...
1 year ago it was 45k km...since then My meter wire doesnt works and I had not reppaced it... I think so it should be 60k km...
can you give an approx estimation of rebore and replacement??

 

[pravin1987]

at 60k, I would suggest a complete replacement and you can ride for another 4 to 5 years.

If you want sell your bike soon, you can do a rebore. Complete replacemet should cost around 5000 with labour . the other way it should be some where near 2000-2500.

I would suggest you to take the bike to HMC service centre and get them a approximate estimate and cross check the same.

 

[Dilshad969]

Sorry for that but I will not take it to HSC coz I am not satisfied with the service they give (You are telling this might be you have a good service center there) rather I will only buy spare from there...
Can you name all the spare required so that I may visit the HSC and get a total cost of it...