Re: Honda Unicorn

Get the valve clearances adjusted to spec and make sure this is done on a cold engine.
Apart from maybe you could try and use a 10w40 oil.

Re: Honda Unicorn

Tappet clearance was done by Honda authorised center, he said that is the max he could alter. In cild start noise is more After riding ~3-5 kms the noise almost vanishes.

I will try for 10w40 at next oil change.

Re: Honda Unicorn

Yes, that it's normal for the noise to vanish on a warm engine.
Am not sure if the mechanic adjusted it by his 'experience' or used a real feeler gauge to get the correct setting.
How many km has the bike run ?
If not a 10w40, even a 20w40 should be fine.

Re: Honda Unicorn

Thank you for answering s1d. Felt sorry for Darshan as I couldn't reply to his query as I barely know anything of the internals. Have had the 07 uni for 9.5 yrs but had never had to open the engine till now. Yesterday got the piston rings changed as a preventive measure at 52k kms.

Honda Unicorn

He said I have adjusted using feeler guage and as per company standards.
It has run 49700.
I have been using shell synthetic from 30000 km onwords. Changing oil at every 5-6000 kms

Re: Honda Unicorn

Did you get it done at the svc ? Were you able to get the original ring set in the standard size ?
Since you changed the rings, i'd advice you ride the next 500km like a run in trying not to exceed 60kmph often and accelerating gradually.
I once tried to get a ring set for my Dio but the two svc's i went to just laughed it off saying 'saar we just change the entire bore/piston kit' and don't sell just the rings. And i did not bother to ask them to place an order or anything.
Even i wanted to get it and maybe change it as a preventive maintenance at 50k on the odo, but couldn't get hold of one.. the scoot has since done another 20k i.e. 70k and is still running well.

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Well then don't worry much.. a little noise is ok considering you have run close to 50k km. Ever changed the timing chain/tensioner ?
even finer adjustments might be possible, but i doubt these guys would put the effort to get it 100% quiet.

Re: Honda Unicorn

Till my failed diy on tappet adjustment it was running so silent. Felt very bad for the bike. Can you guide me step by step on tappet adjustment, if you dont mind?

Nope engine hasnt been touched so far. Everything is bone stock.

Do you recommend changing piston rings for my bike now? What are the benefits if done?

Cheers!
Darshan

Re: Honda Unicorn

Hey,

Haven't been to an svc since the free services. For the last 5 years have been giving it a guy 'Pankaj' in a castrol garage in Goregaon,Mumbai. Have come to trust him a great deal as he has never ripped me off. Been planning a 1400 kms trip and told him to see what's necessary. I asked him about the run-in part but he said its not required. Am not a hard rider, have rarely gone beyond 6k rpm. He also insisted that the bore and piston are good. There was a bit of onset of rust on the tank and frame, that's been addressed right now. Should receive the bike in a day or two after all the above work.

Darshan,

The change of rings help with if you feel compression loss. Even if you don't I feel it's a good preventive measure for a bike at 50k, of which I have heard, a lot of them need full work under 40k kms. My timing chain and rocker were all good.

Lets see how it turns out to be.

Re: Honda Unicorn

Hey man, I am not very good at explaining it in words, I did what I could in my earlier post. You need to adjust the clearances on a cold engine and when the piston is at the tdc of compression stroke and the timing marks align, you will notice some play on the valves(remove spark plug while you do this). Once you get the tdc at compression stroke, loosen the lock nut, and then adjust the clearance to spec (i think the valve clearances will be mentioned in the owners manual.. so check it) and once you have the clearance in spec, tighten the lock nut, close the valve cover and put the spark plug back in.

Here is a similar procedure posted by another user http://www.xbhp.com/talkies/do-yours...nk-xtreme.html

Or Can you try to buy that book which I had posted earlier ?
Otherwise you could try and find the workshop manual.. I have the pdf workshop manual (i think it was for the similar cbf150) but unable to find it at the moment.

If the compression is good and you have no issues, it's better to not fiddle with the rings. Am sure they would last much longer. Do it only if you know a reliable mechanic and you know what you are doing. Considering the dilemma you are going thru with valve clearance, i'd advice you stay away from doing unnecessary part replacements , especially something as important as the rings.

Re: Honda Unicorn

Thanks a lot. Sure I will learn thoroughly and try.

Yes I have the book. They haven't clearly defined how to obtain the correct TDC.

Sure, wont touch the rings.

Appreciate your efforts in mentioning the steps as clearly as possible.

Best regards
Darshan

Re: Honda Unicorn

Hey all. I am in a serious need for help.
I am having a very bad issue on my unicorn. The issue is that if the uphill degree is around 50 degree or more, my bike cannot climb it, if started from idle.
Even if I try to take half clutch and rev-up, as soon as I leave the clutch, the engine RPM decreases abruptly, even in the first gear. Like, if my RPM is 6000 or more while taking clutch, as soon as I begin to move the bike, the RPM decreases sharply and the bike is unable to climb inclined uphills.
What could be the problem? Could the problem be with not enough compression? Or could the problem be with the clutch-plates? Although I don't think it's worn out clutch plates, because I can reach 50km/hr @ 3k RPM, I do suspect that the clutch plate may be too tight. Is there anything as a very tight clutch plate? I also suspect that the mixture is lean, since it is giving minimum 48 in this crowded city. Others say it will give only 40-45. Could a lean mixture lead to RPM not increasing on load?
My bike is CB Unicorn, 2012 model. Even Honda splendor can climb uphills.
Please help me. Thank you.

Re: Honda Unicorn

Mine is 07. Am not sure about the 3k rpm for 50. Mine is usually at 3900-4k for 50. And btw 50 deg is a lot! A ramp is usually around 20-30 deg. It depends on your bike condition and health also.

Re: Honda Unicorn

Hi
Check for loose tappets and valve clearance.

Cheers!

Re: Honda Unicorn

Me too have faced Engine stalling at steep angles , but only during fuel is quite low in reserve . Check with fuel filled well above reserve . ..

Re: Honda Unicorn

Cleaned the Centrifugal Oil filter and the oil strainer screen.

Last time I assumed the strainer screen to be the centrifugal filter.

Centrifugal filter opened first time since the bike was purchased. Strainer screen almost blocked with dirt with less than 7000 Km from previous cleaning.



Tried Motul 20W40 and the engine behaves worst of all times. Facing false neutral and hard gear shifts after changing to Motul.