Re: Honda Unicorn

I dug up my old unicorn after 2 years of rusting, floods ,lying around. Back in 2014 my 2004 unicorn needed a full overhaul , but it seized before I made a decision, I upgraded to a CBR 250, now I made a decision to either rework the bike or completely scrap it and sell it , only time will tell. It probably needs a complete engine overhaul, new crank, new carb, etc, if the engine is work able it will be a miracle, I'll post a few pics of my first bike, holds a lot of good memories for me.I hope to rebuild and bring back the engine to life

HONDA UNICORN - ENGINE - Boring change

Hello experts,

My bike Honda unicorn, Ran for 5 years (45000 KM) (average speed 60 km/h)
Recently I found that Oil leakage in the Engine panel.
I visited Honda service center, to find the issue.
They said, Boring might be the issue.
And it should be replaced soon.


Kindly confirm me whether I have to go re-boring or changing the "boring sets" completely?
And also, I would like to know, after changing the boring sets, how it will impact the engine performance?

kindly help me.

regards,
Jayakumar M

Re: HONDA UNICORN - ENGINE - Boring change

Lucky that your stock bore was able to run for 45000 KMs. Mine was re-bored twice between 37-49 K kms. We had the same bore issue with 4 other Unicorn in my friends group and that too in the 30000 Kms range.

Engine health after re-boring depends on your luck.

You should follow run-in(similar to new bike) either changing to a new bore & piston or re-boring to next size (again new pistons).

There should not be a big difference in performance.

And I heard Hero Achiever bore kit is a direct fit. You may try those instead of Unicorn bore kit. Please check with your mechanic.

Re: HONDA UNICORN - ENGINE - Boring change

Wasn't there any lack on the maintenance part?
I mean that's too bad to accept, 5 unicorn owners losing stock engine below 50k kms.

Re: HONDA UNICORN - ENGINE - Boring change

I would suggest going for a new bore, probably at HONDA ASC.
If you have a trusted mechanic who is good in doing the job, you can approach him too.
A re-bore job would bring up lots of hassles if not done properly.

Re: HONDA UNICORN - ENGINE - Boring change

That's the quality of Honda engines in the past few years. Even my Activa was rebored at 33k. I used to change oil at 1800 -2300 km interval. Definitely not a maintenance issue or because of riding style. I checked with my mechanic and he told that he is also getting many Honda bikes with oil getting reduced problem with few years of usage. But I still love my Unicorn for the gear shifts. Same as day 1.

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I insisted on Hero bore kit because I know 2 2010 extremes which were ripped but their bore failed after 70K kms compared to well maintained Unicorns whose bore failed before 40k. Also read in couple of forums that Achiever bore is direct fit.

Re: HONDA UNICORN - ENGINE - Boring change

My unicorn was a 2004 model and ran 1,80,000 km it seized because I didn't look after it and it was being thrashed n abused, but its one gem of a engine, if serviced and properly looked after you can go on n on.

Re: HONDA UNICORN - ENGINE - Boring change

Yes, I have read that Achiever is having the same engine as Unicorn. And yes, the new Hero OE bores are of good quality.

Re: Honda Unicorn

Guys my friend's unicorn - top end rebuild is going on (replace piston, cylinder, timing chain, valve etc).
I taken the head to the lathe shop.
The lathe guy asks Rs.900 for valve seat and valve guide replacement.
Is this the standard price for this job?
Thanks.

Honda Unicorn 2007 High Revving

Hello Guys,
Few days back bought used Honda Unicorn 2007 model in quite good condition however I noticed few problems in its idling. I will tell you exactly what is happening and what all things I tried doing on it.

Bike was unused for few months when I bought.. I took trial and found one problem of hard starting and few basic issues like high revving which I thought could be because of bike being stationary since long and such problems can be solved.. so the deal was finalised and bike was my home..

Problem: When cold if we throttle in and close.. it de-accelerate slowly which causes irritation while riding as whenever you want to change the gear you engage clutch and RPM goes around 4k.. when engine hot enough after driving 4-5kms Bike revs up high when hot.. RPM goes beyound 4-5k.. even in idle condition it keeps revving.

1] Thought to give carb a good clean.. as my doubt was on choke piston must be stucking in so removed carb; opened fully and gave good clean using carb cleaner.. all jets and nozzles cleaned carefully..choke piston cleaned nicely.. lot of crud and mud removed from float bowl and outer body too.. finally re-installed and tuned in for optimum performance.. But still same issue.. Bike keeps revving in same manner..

2] removed choke cable from carb and tried again.. still the same issue..

3] After lot of hit and trials I got hold of exact fault... Removed Throttle Position sensor plug and revving stopped.. Both in cold as well as hot condition.. Bike idles properly..

4] removed TPS and gave little clean on its revolving knob.. thinking of some dust sticking on it.. re-installed.. No changes.

5] Checked TPS Ohms on mutimeter and it does shows proper functioning .. resistance varies with throttle turn in n out..

6] Gone through few threads of TPS initialization on xBHP by Mr.Subin .. that was excellent tutorial.. connecting battery 12v to CDI wire and giving throttle 3-4 times... like on first throttle RPM should show 1k then releasing it should go to 2k and then 3k and 7k then 5k and again 7k...

7] In my case first RPM shows 1k then 2k then 3k... and then goes to 4k instead of 7k and then after throttle in it goes to 8k and stucks there... So I feel something wrong here.. either Sensor is Bad or CDI Unit?? or I am following some wrong methodology?


Pleas guide me.. All experts here need your help.. Local mechanics are hopeless and they suggest me like " agar sensor nikalke problem solve horay to nikal k rakho" what nonsense.. Honda is not mad to put 12-1500 bucks sensor in carb for no reason..


Need guidance..

Honda Unicorn RR and stator

Hi friends,

I have 2005 kick start Honda Unicorn. Recently I got most of the parts changed; block piston, clutch, timing chain, transmission chain, sprockets.. I have some issues with my bike.

I am facing a issue in gear shifting. Gear shifting is not smooth. Earlier I used to shift gears from high to low when I stop the bike, now I have to engage the clutch to some extent to shift the gear.

The bikes RR + battery needs to be changed as they are broken. Is it possible to use other bikes RR? Any suggestion for battery? currently I use Amaron.

Also can I fit Avenger 180 stator + Ape RR to solve light issue? Had anyone done this before?

Regards,
Prashant.

Honda Unicorn 150 Mods help needed

Hi Friends,

I am new to this forum and this is my second post. I have tired searching every where (online, local mechanic and service center) but have not received any help.

I own a Honda Unicorn 150 (2016) and wanted to add a digital watch and a gear indicator to display the current gear number / position. I have come across multiple hardware online which displays the gear number but I am not sure if or how can the same be installed on Unicorn 150 and have no leads for the digital clock.


I hope this post will not be deleted and it will be great if some once can help me out here

Re: Honda Unicorn

hi guys,i have a 2012 model unicorn,i have installed k&n rc1060 and a custom made free flow exhaust from automech.
i now want to upjet the carb so what size i should use and wat is the stock jet size please let me knw.
thanks

Re: Honda Unicorn

Hi

I am new to this thread, recently my CB Unicorn 150 (2013 model) bike was making loud sound in the engine. I left it in the service center they told to replace the bore and piston cramshaft etc... The bill was a hefty 10000 rupees. But after 3 months now i found that the bore / piston replaced was of honda shine. My Unicorn is not smooth and makeing more noise and heat while riding. What to do now. Also which is the best long life bore piston for unicorn.

My bike has run around 45000 km

Re: Honda Unicorn

Yesterday i went to service my bike. Requested the service person to adjust the tappets since it wasn't done for the past 20+K kms.
I was told that I need to replace the cam shaft and cam shaft holder.
The bike runs perfect no drop in mileage, the engine is smooth and no oil leakage from the cylinder head.
What are the indications that a cam shaft and cam shaft holder are gone ?

Also the bike has run only 29700 kms (2011 model) and no harsh accelerations