Hello bikers,

Yes i was so excite to get Oil Cooler fix on my CBF Stunner when i bought it, and after so much brain exercise i dared to do it , and luckily i got success.
and i am going to share it here with you.


Oil Cooler is almost same as radiator , but Oil Cooler cools Oil . when bajaj launched the pulsar with 220cc and 200cc , in the advertisement key feature was Oil Cooled engine.
Yamaha R15 and Bajaj avenger also have Oil Cooler. question is does 125cc CBF Stunner need Oil Cooler, cause 125cc does not generate as heat as 200/220cc engines. personally i believe that and i have felt that 125cc also go beyond its operating temperature and somewhere i had read that if i reduce only overall 20c temperature of engine, its life span would be double. but it also need to reach operating temperature.

i was scared to do that major modification in my new CBF stunner but still i just wanted that feature in my bike so finally i did and i have been riding it for last one year around 15000km.

First i wanted to use car radiator because pulsars or Yamaha R15s radiator was not available anywhere even not online. so i found this



but it was much difficult to fix it in bike so i ordered new Oil Cooler in Pulsar show room and waited 3 months , finally got new one





I told michenic ( My friend having a tow wheeler garage) to do whole installation, i told him to tel me the main highway of oil circuit and we will divert oils direction exactly from the oil pumps outlet to Oil Coolers inlet and outlet of the Oil Cooler will be directed to again main highway so all oil circuit provided by the company would not disturb at all and whole circuit would get only cooled oil came through Oil Cooler. but he refused to do it because to divert oils direction we have to put a blockage in the main line , and main line was located between the wall of body (out of reach) he was unable to put a blockage . again i started brain exercise , got an idea sirji , main line goes through the joint of side cover and we can block it there. we started operation.

in the red circle is the main lines passage going to whole oil circulation circuit , we just blocked it with thin metal strip , got from tin cover , cut exact size of main line like in the picture bellow, applied some silicone tube and blocked. and made first hole at pointed with red in the picture bellow. thats the side cover of gearbox ( i don't know the right name)



then we made 2nd hole at opposite side on the gearbox body


and made one hole on the opposite side


when we made a hole on the body of gearbox , there were lot of metal wear got inside the main line , its extremely harmfull for whole engine and interior parts , it was critical to clean it inside the line but my friend ( michenic) got idea he just removed oil pump and blew compressed air , all metal wear threw away from the main line .

after removing oil pump it looks like this




oil pump looks like this



again pump and cover was fixed and packed the gearbox.

then made connection ( that mostly used in hydraulic systems) used high pressure flexible pipes that can stand with heat and pressure.



everything visible clearly in the videos at last.

then same way made connection on Oil Cooler



connected two hole on the Oil Cooler to the two hole made on the gearbox, now pump will make pressure and due to blockage , oil will be diverted to the Oil Cooler , and it will come back to the main line and go through whole oil circuit.

Oil circuit before fixing Oil Cooler.



Oil circuit after fixing Oil Cooler.



I fill oil in the gear box and checked , everything worked fine.

i already had ordered digital thermometer to install on the bike


its steel part should be sank in oil to check temperature , i fixed steel part ( thermocouple) in Oil Cooler and mounted display on the speedowmeter , one meter cable was enough( cable should never cut to joint other cable to make it long ,it will display wrong temprature) , its maximum capacity is 110c but oil has never went more than 85c even after 150km continuous ride in summer.

i bought two 12volt dc fan 60mm.



After some viring fan and temperature indicater was ready to work.





engine generally gets too hot that we can't feel the difference after installing Oil Cooler by touching but its obvious that when i touch Oil Cooler its much hot after riding it means all that heat energy is reduced from the engine and it will be exchanged to air in weather. generally it stays at 70c to 75c at 5km to 15km , it reach 80c to 85c at long ride but it can't go upper than 85c , it mean at 85c , heat exchanged between Oil Cooler and reaches the same point as engine is generating heat. other feature for me is if somehow oil is empty i will be able to know that because if theres no oil in the gear box , temperature will not rise in the indicator.

you can see whole thing in that videos, i have done much effort to write this blog, if you like it LIKE my videos.


See how oil temperature arising , it indicates even minor temperature difference.


NOTE : I have just shared what i have done with my bike i don't tel you to do it with yours. modifications may damage your bike.

at last sorry for my inglish i mean English

Thanks to all bikers, Happy Riding