sir i have fitted the kb125 crank into the kb100 crank cases (i t was a major mistake) it is a direct fit to the kb100 crank case , the only thing that is bigger in the kb125 crank shaft is the small end . i have one with me now , the kb125s crank case is wider at only the portion below the cylinder to accommodate the larger bore. you cannot use the kb125 crank onto the kb125 crankcases is because of the variation of the dimensions of the small end

@msranade here is a link to download the parts manual and info on various parts for the KB 125..





SICO - Sanjay Industrial Corporation

Thank you very much sir !

Anna, the parts catalogue mentions 14/41 as standard and 13/42 as optional. my KB125 had 13/42 on it. i looked around for that set-up but couldn't find it. the closest i could get was a 13/43 of the caliber 115 so have bought it.

sarin gave me the same advice but i had already bought the bearings by then. with some help from sarin over the phone and some good videos from youtube, the seals came off quite easily.

from my personal experience, if you buy bearings from an auto-parts shop, they are likely to be slightly more expensive. get them from a bearings stockist. i got skf (sealed) for 120/- apiece from an auto parts shop while the NRB (without seals) from a bearings stockist costed me 100/- each. four bearings means 80 bucks less. its a pittance in today's world but nevertheless its still money that can be spent better.

on my rebuild, i'm living through some interesting times. will post results on my thread soon...hopefully

did you get the ph nos

The old stock KB100 is 14/42....which gives 1:3... Try getting the RX100 front sprocket because now the ratio is very tall at 13/43..I am presently running my stock KB100 at 15/42..without any acceleration problem.
Bajaj 4S and Boxer also came with 13/42 and then 14/42...You can try any one combination.

sir you mean the gearing is short not tall

I had mentioned the ratio getting taller ie.,higher with 13/43 the ratio is 3.3. 13/42 ratio is 3.23,and for 14/42 it is 3 and for 15/42 is 2.8....etc.,
A higher ratio is not preferable for a normal street bike ,and only for dirt, mountain ,and most off road application .
KB125 with increased HP and torque can make good use of less ratio for higher speeds...which is why I said that even in my KB100 i am running 15/42.

it is called short gearing which gives better accleration at the cost of top speed (it has a higher gear ratio than stock) ,and tall gearing gives better top speed at the cost of accleration (lower gear ratio than stock)

My KB 100 got last week

Hi Friends, KB 125 was my first geared Motor cycle I ride.It is my my uncles one.I used to take for my week end rides.It was 1998 and My uncle sold the bike in 2000. But I started searching for one KB 100 or KB 125 in good condition. Since I like this bike very much from my child hood. Hope everybody remember the ad of KB 100 comes in weekly books in olden days. the image combines half of KB 100 and Half of cheetah. Finally I got one good condition KB 100-1991 model last week after 10 Years. But the guy who sold from rural area and He used Petrol-Diesel mix in KB 100 due to habituation of Rajdoot & Jawa yezdi bikes. IT made lot white smoke, I topped with petrol 2T mix, But due to density of diesel , it stays at bottom of tank and smoke ends once petrol started filling in to the carb. I started the bike and ride for non stop 100kms till I reach my home.The bike bring down my age 10 years young, remembering my first ride with KB125. Need some service and parts replacement. At present proudly staying in my stable along with my other 2 stoke warriors.

That's really a nice KB there shankar bro. Pls tel us more about yourself and the bike.

@all
My fuel gauge has not been working for long. Since its the only part which is not working i'm trying to fix it too. Like psr sir said the float is likely to be damaged or the cable might be damaged. I want to know if this can be rectified by myself or do i need a mechanic's assistance.

KB100 - Fuel level gauge not working

@harishkumarko - please read pg 124 of the workshop manual provided by PSR anna. A multimeter and a few basic tools should do the trick.

I wonder if any mechanic can help you with this. for most of them its simple: fuel level gauge not working - change fuel level sensor; still not working - change display console.

From my elementary understanding of electricals, i recommend you do the following:-

1. clean the contacts (bullet connectors/MCs) of the fuel level sensor and the display console. connect everything and then check if the fuel level gauge is working.

2. unmount the fuel tank, take out the fuel level sensor and check if its functioning as given in the workshop manual. if working then assemble the fuel tank and mount it on the chassis.

3. check for connectivity in the wires of the main harness that connect the fuel level sensor to the display console.

4. check the fuel level gauge as shown in the workshop manual. if its damaged, i wonder if you'll get a replacement. you may have to replace the entire display console.

a word of advice - since its an old bike, i recommend that you replace the main harness. i also disassembled the display console and changed all wires and cleaned all the contacts.

all the best

The resistance in the float assembly is Nichrome wire which over a period of time rusts due to water vapour inside the tank...when you have least/no petrol , remove the tank,turn it upside down,remove the float/level sender assembly and you will have the whole assembly in your hand.Now check as per manual ..if the readings are not ok, you will see that the end of the float is attached to a small metal wiper and is touching the Nichrome wire wound evenly on an insulator.when you raise and lower float with hand you will see it moving on the Flat wound wire.SOFTLY Clean this ,and the arm touching it with zero emery . your sensor should be back in action.

Thank you rookieraj sir and psr sir. Just noticed that the brake light wire for the front brakes is also detached from the lever. Need to fix that too. Exams commencing shortly. Will end in mid may and will be jobless. So I thought I should practice DIY. I'll be back for more advice. Thanks again.

With scarcity of OEM parts, the front brake light switch on my bike has been disconnected on purpose. Tried a couple of them but they either didn't work while one malfunctioned leaving the brake light on always hence eating up the battery :P