quick carb clean?

[beginnerMX]

Hey guys noob to bikes here but wondering is it ok or bad or pointless to take off the air filter and spray carb cleaner in carb past the butter fly valve with the bike running to clean up the carbie abit? after my last ride butterfly valve is abit dusty and bikes bogging when giving it half to full throttle.. not game enough to pull the whole carb apart so wondering if this would benefit some what? or what about just pulling the carb off and leaving it all intact in a bucket of carb cleaner/petrol etc overnight.. Cheers.

 

[beginnerMX]

Better yet is there something i can add to the fuel so it cleans up the jets as im using up the fuel. this is for a lifan 150CC engine.

 

[aussie_140]

hey mate, you probably have a bit of water in the bottom of your carbie, you should take it off from the manifold and then there will be 4 screws, unscrew them and give the bottom of it a bit of a blow out then put it back together its pretty easy just give it a shot

 

[beginnerMX]

this is a huge possibly as i went through nice puddles ill give it a try thanks mate!

 

[aussie_140]

haha ride hard! give me a message if you get stuck with anything

 

[beginnerMX]

pulled carbie apart an cleaned it an jets was all clean anyways, but still did it, so wat happens now is at idle if i give it abit of throttle bike backfires a few times an just dies.. my next thing is to change the spark plug? what could be the problem? do valve clearances change while riding? as this bikes 4 years old.. got it second hand was running fine last few rides..

 

[my67xr]

valve clearances-
.003" intake, .004" exhaust, imperial measurements
.076mm intake, .102mm metric measurements
incase you cant find it-
http://www.miniriders.com/motor-tutorials/24965-how-set-valve-clearances-horizontal-engines.html

did you take the pilot jet out and check all the side holes are clean?
and the maiin jet tube out and clean that too, as well as the main jet.
the ports that the jets screw into can also get dirt in them.

 

[beginnerMX]

because the carbie looked spotless inside i didnt remove the jets just sprayed carbie cleaner in there, now best way to explain my issue now is with choke on i think (lever down mikuni carb) it idles an revs fine if i turn the choke off (lever up) it dies about 30 later or if i rev it, it pops/backfires 1-3 times an just dies i think its lean with the choke off?

Edit: Also whats the adjustment screw under the carb? i no the one on the side is idle but whats the one under it? air? cheers.

 

[aussie_140]

not to sure mate. the one at the bottom probably makes fuel come out of the bottom of the carby if you need to get water out in the bush

 

[rotn50]

because the carbie looked spotless inside i didnt remove the jets just sprayed carbie cleaner in there, now best way to explain my issue now is with choke on i think (lever down mikuni carb) it idles an revs fine if i turn the choke off (lever up) it dies about 30 later or if i rev it, it pops/backfires 1-3 times an just dies i think its lean with the choke off?

Edit: Also whats the adjustment screw under the carb? i no the one on the side is idle but whats the one under it? air? cheers.

Mate it will die when the choke lever is up because that is choke on not off, choke lever down is choke off, hence the reason it runs fine. So choke down is off and choke up is on, we want it down so choke is off, and enjoy your rideing.

 

[rotn50]

And yes there is 2 screws on the bottom, obviously the lowest one is the drain screw and the one level with the top of the fuel bowl is the air mixture screw

 

[beginnerMX]

LOL an heres me an my mates thinking lever down is choke on! lol my bike never idles with choke UP on even when cold.. is this a bad thing? thanks heaps!! ok so with the carbie clean, the bogging out at half an more throttle playing with air mixture will help this? thanks rotn50

 

[rotn50]

All engines are different, some need choke some don't, if it doesn't then there is no prob, as for bogging down the air mixture screw may help, screw it in all the way and back it out anticlockwise bout 1.5 to 2 turns(2turns being 720 degrees) but if the carby was a mess before cleaning it, it may need replacing.as its what's in the casting you can't see, make sure the carby slide needle clip is in the middle setting or lower. There is 5 settings with the top being lean and the bottom being rich, these donks like running on the richer side. Good luck dude

 

[tubes]

ok so with the carbie clean, the bogging out at half an more throttle playing with air mixture will help this? thanks rotn50

glad you got it sorted out.. main jets might need to be a little bigger so worth checking that out also.. warm the engine up and hold the throttle a little before wide open (so its not overrevving) and turn the idle speed screw (the one without the spring) a few turns in until theres no popping or bogging.. hope that helps mate

 

[beginnerMX]

thanks heaps guys wheres the carbie slide needle? ill search an im sure ill find cheers for all the help though! appreciate it heaps!!!!

 

[rotn50]

undo the top off the carby, the part that the cable goes into and remove the slide, the needle that is hanging out of the bottom of the slide is the carby needle, take the cable and spring off and push the needle out and you will see the little clip on it and you will notice there is 5 notchs on the top of the needle to adjust.

 

[beginnerMX]

awesome thanks you think this bogging giving it half to full throttle straight off each gear is to rich or lean? i will try both settings though..

 

[rotn50]

depends on the current setting, there is five settings, bottom being rich and top being lean, if its running to lean it could be bogging, but until knowing its setting, we can only assume.

 

[beginnerMX]

ok thanks mate, ill have a look tomorrow an report back. cheers.

 

[beginnerMX]

clip on needle was on the bottom setting i put it up 1 but have no idea how this spring and thing go