Yes, I can hear the intake note in the mid RPM and after cleaning the air filter I can feel slight increase in acceleration. Today I opened the ngk spark plug for a cleanup I noticed the spark tip is light brownish in colour and no carbon deposits on it. Is the light brownish colour is due to lean air fuel ratio mixture?

Yes, nowadays getting a speed above 70 is quite a dangerous in Kolkata as number of 4-wheeler was increasing day by day. It is also dangerous because of those people who don't take care by looking out for vehicle while crossing the road and they simply run to do it and when suddenly a vehicle come toward them, then they become confused and start a circus juggling in the middle of the road.

Finally this post is up and i will post how to change the bore piston kit so that the performance of your bike is good.
First let me come to my problem which prompted me to open the bore.
The problem were as follows:-
1. From February this year the mileage suddenly decreased to 68 k pl from 78 k pl and no amount of servicing would increase the mileage.
2. On DE-acceleration there was a slight ringing noise which indicated that the rings were not sitting properly and was vibrating in their grooves.
3. Just two months ago the engine was opened and con-rod was replaced but bore was good so was only honed but we made the mistake of not changing the rings.
4. The engine was loosing compression once hot and the tuning was rising to 2000 rpm when hot.
5. Valve leakage was not detected as the engine was not showing any problem when cold and the kick was also tight indicating valve seating is correct.
6. During last few days the mileage decreased to 55 kpl.
So here are the the procedure.
For opening the head follow the following procedure:-
1. Open the right side panel and open the nut holding the rear footrest bracket.
2. open the center nut which is holding the silencer. do not force the silencer to open.
3. open the two silencer nut from the silencer mouth located at bottom of head.Now remove the silencer.
4. open the carburettor cover(black cover under the tank) and remove the bolt holding the intake manifold to carburettor.
5. Open the gear lever and magnet cover.
6. Open the air injection unit.
7. Open the timing cover and match the timing by placing the magnet T mark against the casing mark and also seeing the mark on the timing sprocket matches with the head mark. Now open the two small nut on the timing sprocket and remove the sprocket.
Now open the small bolt holding the head at the side just besides the timing cap and then open the 4 head bolts in crisscross pattern. Remember always open the side bolt first and then the top bolts.

Many confusion are there on xbhp on tuning of carburettor. See the tuning from the spark plug-

The timing mark matched to mark on engine casing:-

The head bolt removed and the intake manifold removed from carburettor-



You can see the carbon deposits in the above picture.The o-ring present in the oil return gallery is responsible for stopping engine oil from entering combustion chamber. If it gets damaged the bike will smoke like 2 strokes.

The picture is self explanatory. You can check the exhaust valve by opening the spark plug and focus torch through the hole. Now slowly rotate the engine by shifting the gear to first and moving the rear wheel on main stand. You will not have any difficulty as there is no spark plug so the compression is nil. After rotating for about half rotation you will see the exhaust valve will rise. Now look it in torch light and you can see the color.If the valve is red then there is nothing to worry as tuning is correct and petrol is also of good quality.

The old bore was worn at one side. So it took the shape of an oval and thus the rings were floating without touching the bore at on side and touching other three side. The ring gap was 0.5 mm and was same for top, middle and bottom. The problem was not with gap but with bore being outof round.

We were inserting the piston and ring to check the ovality of bore but my mechanic came and just gave a look to bore and told exactly where the bore has worn. Now you know what 20 years of experience mean.The bore was worn in this way because the clutch side of the crank-pin was worn and thus the con-rod was giving more thrust to that side.

The splendor and joy piston are placed. Joy piston has larger skirt and also landing for absorbing thrust of combustion force. You can fit the joy piston in splendor but cannot do the reverse as it will cause rapid bore wear and rattling of piston in bore.

The DID timing chain which cost Rs.174 and the OE chain cost Rs.100. If you cannot find DID then go for Rolon or Diamond but do not go for OE.


This the USHA bore kit.
Why i went for USHA bore kit?
The first time i went for engine rebuilt was at 1.24 lacs km. At that time i bought a OE kit which had USHA liner and piston. The bore kit ran for another 1.20 lacs Km and while opening there was no smoke and the bike was returning a mileage of 70 kpl. During the tenure of this bore The bike sometimes used to return 100 kpl on NH and also touched 110 Kph effortlessly. AT 2.44 lacs another engine overhaul was done and OE bore kit was used but it had piston of SAL. The bike started consuming oil with new piston and when the head was opened after 1000 km at first service the combustion chamber was full of oil. Then again oversize ring was ground and fitted.The bike ran for 20k and seized. Then the bore was bored and MAHLE piston was used. That ASS**** made the clearance so less that when heated the engine will not idle as the piston was expanding and jamming the bore.The bore lasted for 30k and this time i decided USHA bore as i had previous experience with USHA and also the piston is semi-forged and silicon mixed so it resist thermal expansion.



The valve are lapped using hand. I never go for machine lapping as in lathe and instead lap with hand which gives superior results.

The USHA bore liner is so smoothly polished that there is no risk of seizure. Moreover you can see the liner mark is not there as in OE bore and it is seamlessly fixed with the casting thus allowing better heat transfer.

The usha piston is made in honda foundry, Japan.The rings are supplied by Riken, Japan. The OE piston set cost only Rs.450 but USHA piston set cost Rs. 750. So you can imagine the quality difference.






Difference after bore fitting:-
Since we regularly use our bike we do not notice how much gradually the performance is decreasing.
After fitting the bore the low end torque has increased and the bike is eager to pull wheelies. IN my joy the low end torque is so good that even if the engine will be idling at 1000 rpm if you slowly release the clutch in first gear it will pull without touching the accelerator. This was missing which gained after bore was changed.
Difference in USHA bore-
Even though the ring gap is so less and the piston is tight then also the bike feels free unlike in OE kit where we have to run it for freeing the engine.

OT : Pinaki ji that pipe inside my ZMR is chewed by rabbit & now it has only lower part , should i replace it ? The SVC guys said no problem with it , it would be good as bike will get more air supply .

@ sibun very informative post , when you post all details , try if you can put it inside a pdf , come handy when offline .

There is no problem with that. Usually it is located under seat and water doesn't get in there. But if you want replace it. I don't get the logic that it allows more air in. the air flow is restricted by air filter. so even if you remove it then also it doesn't give any appreciable difference.
I can put it in pdf but how to convert it into pdf.

Ok so there won't be any pro or cons with it , but will replace that pipe if i found it ( though it is real hard ) .

You need to create a PDF using PDF Creator like Adobe , nitro , foxit etc.

Many moons ago one late noon when the roads were quiet I was riding near that speed near park street and a thela popped out of a side lane , not the whole of it mind you ... just the front part of it .. I still could not see that thela-wala pushing behind the thela when I hit it with all brakes locked hard and engine braking on enough to grind the gear teeth smooth . My rx-135 slided under the contraption and I somersaulted cleanly over the top of it and landed on the footpath on the right side about 5mtrs ahead . Nothing much happened to the bike but I broke 2 left side ribs(hairlines), a finger and nose bridge other than being thoroughly bruised all over . Many many years later now sometimes I still half expect a thela to come out of a perpendicular side lane suddenly . Actually I never saw that thelawala even afterwards(i wasn't looking then) or ever, but i always remember him whenever i get an throttle urge on a road with side lanes , i.e all of this city .

You oiled the foam air-filter elements correctly after cleaning, no ? Brownish is the right plug colour for a correct tune(whitish is for lean), no problem .

They always say things like that when they don't have the part in stock .. it's shouldn't be more than 50-60 bucks . Every time I have removed or altered a part of these simple bikes I've had some other problem arising out of it later on . I guess there aren't many parts on it that is not essential in some way. Better replace it as soon as you can lay your hands on it, earlier than monsoon . Particularly the paper element air-filter of the ZMR would be rendered useless once wet and that certainly is more expensive than this tube thingy .

Disconnect the battery and keep it over night, then connect battery, start uo bike and let it idle for 2 mins, then rip the hell out of the bike for a few kms continuous.

Why ??

@Sibun
How much was piston ring to ring grove gap ?
How much was the ring end gap at top,bottom,middle in the cylinder ?

Hi,

My 59048km right now,

here is the picture of my Chain Index mark of the rear axle which is stayed last postion.



My mech earlier said it need to change, but I declined stating....I have no mood to invest any money unless battery charging problem get solved...now that I feel it ok, 2nd week though...can't be sure before 3rd week.(Thanks a ton to all of you guys for help and support earlier)

Anyhow....Do I need to change the chain ? I don't have any problem though...

If yes how much does it cost ? Do I need to change the front and rear sprocket too ?(asking this coz read somewhere that if the whole system change at the same time,chain last long) How much does those 2 cost ?

So if answer is yes ; Can any one quote the following stuff

1. Chain cost = ? , Part Number = ?
2 Front Sprocket cost = ? Part No = ?
3. Rear Sprocket Cost = ? Part Number = ?

Front sprocket can be seen in this picture.......



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This problem is regional rather consider it is bike problem; In my state West Bengal our new government promised the Kolkata transform into London by any means. So the 1st thing they implement is to check all old 2 wheeler pollution & worst case cease the bike.

for that matter most cops (not so well informed sub-ordinate got instruction from their upper management/sergent with ancient bullet/geep which served them since days of British Empire) to stop older bike...how to do that in billions of vehicles that enter in the city everyday ? "Stop those 2-wheeler which contain amber color indicator...no matter how it looks or maintained/make"

So now a days bike stoping/fishing by cops/green police rate in kolkata high..it is really annoying every-time to show pollution cert/insurance paper.

So as you guess already,what next I'm going to ask here....please let me know which HM's model indicator compatible with my bike ? At Least I want to change the front those if not possible to rear one ?

here; -



Please mention the;

A. Clear lens indicator cost = ?, Part No = ?
B. Cost of 10w amber/orange bulb = ?

Thanks in advance......
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One more thing I need to said here,

After installing the new "GENERATOR ASSY FLYWHEEL" (as written in the box),my mech connect the resistor cable (Pink one) in the respective socket, As I asked why bother as he dead against it earlier, he replied he don't want to take any chance....

so my que, is it advisable to disconnect that thing ?
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P.S:- Here I got a Part Number crazy Spare parts distributer, else thing don't work so asking part no for those item.

Atleast the front sprocket looks worn , you can replace the chain sprocket set . Sometime back a splendor chain-sprocket set (diamond make) was costing around 600-700 Rs . Even now, it should be around that price for the passion too I think . Anyway check a shop . Ask for the genuine diamond brand kit only .

I've changed my blinkers to transparent-lens & orange-bulbs by using the lens from the new Splendor-pro model. Rest is same. This was possible because the lens from splendor-pro is an exact fit on splendor/splendor+ . Cost was Rs 25 per lens and Rs 10 per bulb , total = Rs 140 and 20 minutes of work .
What you need to do is find out which current model hero-honda bike uses the same size(dimension & shape) but transparent lens on it's blinkers . Maybe the current passion-pro does ? Will keep an eye out .

Will get it replaced if i found it . As prevention is better than cure .

Why ? I don't have any problem , just the thing mouse chewed that pipe . So why to rip ? & why to disconnect battery ?

I have changed the whole sprocket before 2 years costed me 600 rupees . I think part number won't help you as one need to tell the no. of teeths to shopkeeper .

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Before several years i changed the covers to swiss made white one but they are not as pure transparent as comes with the bikes now a days .
Note that only the glass of new passion pro indicator won't fit to passion indicator as bulb direction is different in both .
Better get the whole indicator of new passion pro or some led type ( like the one in duke ) to save battery . ( But need to change flasher too for led type indicators )

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If that resistor is new or having no problem & alternator is also new then connect it to avoid overcharge of battery . If you feels battery going week you can disconnect it .

The process I mentioned above was the methode used to make the ECU recalculate the AFR in cars, and since the ZMR has a similar closed loop fuel injection, I believe doing so will help it make any necessary changes since your intake has been altered, though not by choice. Damn em rabbits.

@neel- Do not go for original. It is like a lottery system. If you get ROLON/DIAMOND then it is good but if you get Hero chain then it will not last for 10K.
So directly go for ROLON/DIAMOND brand. Just ask then for old model passion.
Front sprocket - 14 TEETH
Rear sprocket - 44 TEETH
Ask for small rear drum. The present passion have bigger rear drum and they will not fit.
If you want to modify your gearing then you can go for splendor+ or joy sprocket kit.
Splendor+ - 14 Teeth front and 43 teeth rear.
Joy - 14 Teeth front and 42 teeth rear.
Cost for Rolon/diamond kit is Rs.540. The printed Mrp is Rs.568 but they sell it for Rs.540.
Regarding government policy they are the most competent fools and can do anything they want. This much in the name of democracy.
They think that the old bikes are maintained like there government vehicles.
The CM of your state is one crazy fellow and for changing Kolkatta into London instead of changing system they are harassing public.
Regarding white glass you cannot fit passion pro glass as they have different mountings and have same mountings as passion+.
Instead go for complete change of all four indicators to white ones.
Do not go for OE as they are manufactured by UNITECH and company charges Rs.135 each. Instead directly go for UNITECH as they will cost you Rs.100 each. So for same thing you are paying extra for Hero honda packing only.So always go for UNITECH or LUMAX.
Bulbs go for Phillips or Swiss- Cost Rs. 20 each.

Yes, you are right Above_All , in my case there is no option to change the glass only , after seeing Pinaki Jee's reply I'm gone for local research....and got the info,

The retailer who stock all HH spare told the same and his quoting is 130/- each + 15/- orange bulb which he going to order from parts distributer from Kolkata... delivery date = infinite. Then I visit to bajaj spare stockiest,they show the glass which can't be fit without damaging white plastic where the bulb mount. The glass comes with 2 metal screw cost 15/- each without bulb,but there is no screw mounting point inside the plastic casing in my model.

Here what it looks like

Front


Back or Inside


Those front sprocket not universal for all 97.2 cc bike ? You mean whole sprocket mean front and rear with chain ? or without chain ? or only front with chain ?

As Pinaki Ji also mentioned, What is the meaning of "chain-sprocket set" ?

Is it come with chain + Front sprocket + Rear sprocket ?....please confirm.

Resistor is not new, it came with bike which 11 year old now....but whole alternator assembly is brand new (2 week old). Battery can't able to to lit /function any side of turn indicator without engine running support. It hang in the middle....Thats it...