Leaderboard

Carburetor rebuilding Before dismantling Work in progress Clean venturi New power piston Float adjustment New primary jets New accelerator pump After rebuild Lessons learnt Read the manual fully before beginning. Don't read one step, do that step, read the next, do the next. Some important information is at the end. Most Aisan carbs are similar. Therefore, these lessons are valid for a wide range of carbs. Remove the carb from the manifold, take it to a place with good ventilation, turn it over to drain any petrol in the float chamber. Do the rebuild in a well-lit, well ventilated place. Lay an old towel on a large table in a place without clutter. Some tiny bit will certainly fall out. An indoor location without clutter helps in this situation. You don't want to crawl under beds with a light hoping to find a 3mm spring that flew away! an old towel or thick cloth prevents the tendency of stuff bumping and rolling on the table. Plenty of small containers, labels, pen and paper, small bags Phone. Video every step of disassembly. Narrate stuff as you go on. Like "this nut has one copper washer. This one is little larger than the second and has a spring washer. Take couple of photos from different angles in tricky places. Video the assembly as well. when you missed one bit during reassembly you can pinpoint at what point things went wrong instead of going crazy. In addition to the usual tools have a 9mm deep skinny socket, long needle nose pliers. Proceed dismantling stepwise. Video everything, label and bag stuff then and there, take notes/narrate. Preserve every bit that you find. After completely dismantling, start cleaning. first remove the gasket residue. Don't use metal bristles to unclog small pores. Use carb cleaner and nylon bristle or compressed air. Check all the mating surfaces for flatness. I wanted mine to be 0.05 mm or flatter. Carb is a delicate piece held together by small screws. It won't hold much torque like bolts. So, ensure all the surfaces are quite flat to begin with. Mine had 0.5mm unevenness on the float bowl mating surface but didn't give any issues. Intake manifold had 0.6mm and gave issues- made me do this rebuild. Wash out everything with liquid soap and copious amounts of warm water. Don't use power detergents or soap. The particles can clog up small passages and nozzles. I used the pressure washer carefully. Make sure every passage is opened up with pressured air or carb cleaner. Again, don't use metal bristles. Buy the rebuild kit. Some gasket making paper, fresh vacuum tubes. Check what parts you have got in the kit. Have the exploded view of the carb printed. Pay the disassembly videos on the computer; last one first. Get the video rolling on the phone and go back to putting back the carb. Replace everything you got new in the kit. Make sure throttle plates move freely, pistons move freely, screws and bolts are tight enough. Mine doesn't have a sight glass. The only method to make sure your float chamber is filled up to the spec is adjust the clearances as per specks. Needle to float is 0.9mm. Float to brim is 7.5mm. Triple check because if it is wrong, there's no other way to check the level without taking apart the whole thing and measure the clearances. Adjust the accelerator pump travel to speck. Adjust throttle opening angles of the both primary and secondary and choke to speck. To set secondary throttle opening angles, you have to open it by applying vacuum from outside (by sucking in air). I don’t have a throttle plate angle measurement gauge. I have devised a mathematical method of measuring (calculating) throttle angle with several measurements using a caliper. Here is the calculation. First measure dimensions a to e with the throttle fully closed. To set the throttle to some given angle, calculate x and set the depth x measured using the caliper. It should work as well or even better than the angle gauge. When bending the tabs to set angles don’t bend them back and forth like crazy with a pair of pliers. Instead use a small G clamp. Bend by slowly closing the clamp and check. If it needs to be bent some more, close the clamps by another turn. Repeat till you hit the specs. Check al the vacuum tubes are snug. Temporarily plug those that you are not using currently. Lubricate the springs, levers, shafts and the whole moving sliding mechanism. Make sure all open and close all the way before putting it in the car. Fix the carb, put back what you removed, fire her up, tune the idle, throttle, and AC idle up. Enjoy the happy purring! Because the throttle response could be changed, take a test drive. I had a crappy secondary throttle before. I didn’t realize it till I took apart everything. Now that everything is working as intended, the throttle is more responsive. When this pandemic situation eases I'll take a test drive. Perhaps burn a few donuts!

DIY is always the best. It's really what these restore projects should be about. I did find an uncle in Piliyandala who seems to know his way round carbs. Might be a good contact if you ever need professional help.

You came very close to the proper cold starting procedure. Yours might have required different sequence. Proper cold start process with auto choke is 1. Floor the gas pedal once swiftly. This engages the accelerator pump and releases a puff of petrol above the throttle plates. And turns the cam lobe that closes the auto choke if it's sufficiently cold. 2. Immediately turn the key and start. The rich mixture will air out with time. 3. Don't move the gas pedal till you reach operating temperature. Once the engine starts going, it will generate enough vacuum to pull a vacuum diaphragm on the cab pulling open the choke plate and keeping it locked open. Trying to pump/flicker the gas pedal will prevent the required vacuum from building up to close the choke plate. Or it will puff out too rich mixture ultimately wetting the spark plugs. At that point you have to wait for a long time for the plugs to dry and mixture to vent out before attempting again. There's some YouTube video on this which I'm finding difficult to locate.

Job well done! Hats off! Brings back so many memories of my father and I taking apart this carburettor and putting it back together. As for the Auto choke, my car never had one. Most of the mechanics who looked into it said that it must have been removed by a previous owner. Without the Auto Choke, cold starts were difficult, but then after taking apart the carburettor and after consulting several experts, we learnt to live without it. The trick was to pump the throttle twice, pull the manual choke under the dash, rest the foot on the throttle and crank the engine. As soon as it starts, give it two light blips and she continues to idle okay. My father and I were the only ones who could get the car to start first go on cold mornings, ?

Thanks @tilvin. Had a look at your profile and saw that you are not a newbie to AL. I was rebuilding the carburetor and here you are asking if it's diesel or petrol? Injector pump? Injector nozzles and the like. It's unlikely that you are a troll (or are you?). Has lockdown got the best of you? Has the moonshine started working? Or smoked something different? If it's the last, care to share some with me? Edit - or is your account compromised?

Great job...?. Congratulations...?. How about the nozzels in injector pump? Did you pressurize those? Better do injector pump calibration using specialized tools...?

It has a carburettor. What do you think? ? True that. My father and I may have taken the carburettor apart several times, and we would sometimes struggle for days without success. It would either idle poorly or have trouble starting up in the morning or have flooding issues. Finally when it was time to restore, my mechanic did an immaculate job restoring the carburettor. He even taught me how to do a simple tune and set the screws properly for idle and fuel. Good carb experts are hard to come by these days, so certainly helps to know how to take them apart and rebuild them. Easier said than done of course. Glad the manual is helping. ? Certainly handy to have around when you are taking a carburettor apart.

Sadly that's a no-no. I travel from Yala to Palk strait for work everyday so I expect atleast 13.45769420 kmpl average.

Thel hondata wada. 12kmpl with super diesel.

Thel kohomada weda karanne?

Wish you all the best on your DIY task on your car....?. Meantime, does your car petrol or diesel?