Honda cb unicorn [ gear problem]

Model : HONDA CB UNICORN /150 CC
RUN : 15000 KM
YEAR of MFG : 2013

Problem arise recent that top gear [ i.e 3/4 th]of the bike's accelerator behaves as it is on 2nd or 1 st gear, No smooth pick up/acceleration .Its like holding the bike to backwards or its jammed the chianwheel, RPM jumps to 8000 to 9000 . At full acceleration bike top speed near about 60/65 [ tested on a Aero field ] At first I though it was clutch problem or air filter so i changed both .but problem remains.

Need help .

Re: Honda Unicorn

55500 KMS update:

Lost compression one fine day and found valves to be an issue. 48000 valve and re-bore was not done properly as per mechanic. He even opened things before me and showed few rubber washers missing which led to valve failure. The other reason he says that the valves were never changed at 48000 KM repair work.

So I had to spend another 5000 RS for the rebore work.

Last time instead of reboring for stock +.50, my original bore was rebored for +0.75 which cannot be rebored again.
It led me to procure a new second had bore from a 2007/2008 model scraped Unicorn and rebore it to stock +0.25 size.

After 500 KM running-in, changed engine oil to BP Synth 10W30 which i purchased online for Rs.380

600 KMS completed and I am getting a good fuel efficiency of 55KMPL (@45-50KMPH) when checked with 12 liters of petrol. The mechanic confirmed this to last for another 50000 KMS if I drive it the way I have been driving it all these years.

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I think the bore has served its life. You can re-bore the same cylinder to stock +0.25 size. Should also check if the valves & valves guides are good.
Valve/Head lathe work + Spares + labour will cost less than 5000Rs.

BUT ensure the person who performs the repair work is trustworthy and is capable.
My Bike was rebored at 37000 & 48000 KMs by a trustworthy neighbor who did a incomplete work.

FYI. The new Cylinder Kit (With piston) costs 4100 Rs. This is excluding the Valve/head work or spares.

OffTopic: The 220CC Avenger Cylinder kit is priced at only 1900 where as our Unicorns 150CC cylinder kit is priced at 4100

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Are the vibrations getting vanished after crossing 50 ? If so, i think it is normal. Even mine does that around 45-50KM mark. The best speed to cruise in Unicorn is 60KMPH.

Must be an issue with the clutch plates.

Re: Honda Unicorn

High RPM-low speed, this could be due to bad clutch plates too.

I have seen some Unicorns developing engine issues as early as 40k kms.
If you notice:
- smoke on revving
- dip in engine oil level after few kms
- oil in spark plug tip
- reduction in power/mileage
then what your mechanic said could be right.

And, it is better to replace the cylinder kit, rather than going for cylinder boring.

Re: Honda Unicorn

I have a 2006 model Honda Unicorn 150 which has completed 73000 kms of trusted run. When I gave it for fork oil and seal replacement, the service engineer told me that the engine oil is geting burned and white smoke is coming from the engine. I have observed at around 69000 kms that I need to maintain the engine at a higher rpm than before to attain particular speeds than earlier.He suggested the replacement of cylinder kit. Is it so early for the cylinder kit to fail in a honda unicorn? What could have gone wrong? Possible solutions? Is it better to follow what he told and replace the cylinder kit? Please help.

Sent from my Redmi Note 4 using xBhp.com mobile app

Re: Honda Unicorn

Better you have posted in Unicorn 160 forum.

Engine kill switch can be installed provided entire left and right handle bar switch console is changed.its easier and safe rather than installing only a kill switch. Pulsar 150 full switch gear control can be installed for a total of Rs2500. Many have tried in Hornets.You tube it.

Re: Honda Unicorn

Hi friends, I am having vibration near petrol tank in my cousin's Honda unicorn even around 45kmph . Any suggestions?

Also, I think it takes up all the gears before I even reach 45kmph. Is that the way unicorn has the gear ratios?

Re: Honda Unicorn

Hello all,
I have a Honda Uni 160, currently I am planning to install a kill switch on the same. I have an idea of the Bajaj kill switch wiring but in Honda I am unable to find the cable. Honda CDI colour coding have much difference as compared to Bajaj. Can anyone help me for finding the engine kill wire code??

thanks..Jaisankar

Re: Honda Unicorn

Many many thanks bro for your wise suggestions .... I will definitely keep them in mind

Re: Honda Unicorn

Can any one give STD no of turns for carb setting factory setup

Re: Can I go to ghat roads with my Honda CB Unicorn 150 cc???


In city traffic, there is some room for error, because of generally low speeds and driving conditions that we are used to. However, driving in the hills requires a very different style to driving on flat roads in the plains. This is because of several factors like much narrower roads, steep inclines and descents, blind curves, the presence of inexperienced ghat road users that pose a serious danger to others, and so on.




Use the brake as often as you need to It may sound very basic, but using the brake on the hills becomes all the more important because one may not be used to the high levels of inclines; balancing the clutch and throttle becomes tricky. Loads of inexperienced ghat road users seem to forego this basic rule and get on the wrong side of local traffic.


The usage of right gears is CRITICAL One can get away with things like driving in fifth gear at 40 km/h in the plains, but in the ghats you need to remain at least one gear higher than normal. While going downhill down a relatively mild slope, for example, try keeping the bike in third gear, because it gives you a little more torque and reduces the effort required by the brakes. NEVER coast in neutral because you are opening up opportunities for brake failure.


For once, don't worry about fuel economy and concern yourself with safety instead. Downshift regularly around bends Shift down into third gear at least (preferably second in small petrol engines) for a sharp turn. This reduces the chance of you running wide around the corner. If you notice, several cars come around corners too fast, leaning heavily and run into your lane. This is because the driver is in too high a gear and struggles to maintain the right lane because of lack of torque.


Be patient while overtaking Unlike our highways, the narrower and often blindly curving ghat roads don't offer much view of the road ahead. So if you're stuck behind a slow moving truck, remain there until it's safe to overtake and you have enough room and visibility to overtake safely. Also, don't lean on the horn after you horn initially - the truck driver or bus driver knows you're there and will usually give you room to overtake. NEVER overtake around a blind curve because it might just be your last pass. Use the horn around blind curves This is especially true during the day, when there is no headlight glow to warn you of oncoming traffic. Honking around a bend lets other road users know you're there, and gives them a chance to give you room to pass safely. If you hear someone else honking, horn back and slow down. Give way to uphill traffic This is the golden rule for the ghats because cars, bikes and heavy vehicles especially coming uphill require a lot more effort to take off from standstill if forced to stop. Pull over and let them pass, even if it means you stopping and waiting from a distance. Pull over in a safe spot if you want to stop Never halt your car in a narrow section of road even for a short while, because it could hold up traffic, or worse cause a serious accident. Try and stop at a place where vehicles from both directions can see you, even it it means getting off the tarred surface on to gravel or loose stones

Important Engine prospective change gears when needed this will help for good engine life
Do a oil change before check brakes

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few posts in the unicorn thread means less issues, this explains the quality of the engine

i have completed 80000 Km and no major work done with the engine except oil change and Tyre change.

Planing to change the clutch plates after 1 Lac Km as they are still in good condition

Can I go to ghat roads with my Honda CB Unicorn 150 cc???

I have one Honda CB Unicorn 150 cc (one year old & 12000 km covered) .... now my query is --- can I travel on Ghat roads of India with this bike

Re: Honda Unicorn

At 5000 to 5100 RPM, the bike cruises at 60KMPH on gear 5.

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Mine was from the last batches of Unicorn (March 2010). Noticeable difference was

a) Paper type air filter in Unicorn where as viscous type air filter in CB Unicorn
b) Change of rear view mirror shape
c) Change of the Clutch cover and Magneto cover design.
d) Of course change of stickers from Unicorn to CB Unicorn.

My bike felt heavy than the new Unicorns. But it is just my opinion.

Honda is recommending 10W30 for new Unicorns but my manual does not recommend any specific grade.
It only has a chart on what grade of oil to be used based on the temperatures.

No answer for your third question.

Re: Honda Unicorn

Just check out shine thread, it's quite pathetic and inactive. Shine is owned by many.....

Re: Honda Unicorn

hi everyone this is my first post on this thread, i'm planning to buy a used CB Unicorn 150. I have a few questions...

1. Whats the difference between Unicorn and CB Unicorn?
2. Whats the Honda recommended Oil for the CB Unicorn?. ( Brand and Oil Grade )
3. Despite so many people owning the Unicorn, why there is so few posts in the unicorn thread? ( i mean only 319 pages.... )

Re: Honda Unicorn

If the clutch is bad, then you will notice that the bike is not building speeds though the revs climb high.
One test would be to ride your bike steadily at 50kmph on 5th gear and take a note of the RPM.
Compare it with another Unicorn in good condition and see if your bike runs at higher RPM than your reference bike at the same speed.