cns carb ! beware!!!

so my bike started to bog a little and leak from the over flow hose and also the idle suddeny would go out off and on pluss my choke was all jacked up it was making my carb overflow and the motor run leaner when turned on !!!!! the choke is suposed to richen the mix on this carb !... ok easy fix the float bowl needs to be adjusted to close sooner so the fuel wont fill the bowl to the overflow post...thats what i thought the prob was.....

so i open up my carb and i find the float chamber filled with plastic hunks and strands all half desolved and everywhere !!! no way ! my idle jet was clogged with it and it was all over and in every passage !!!


so i clean it up and give it a warm soapy wash and blow out all the ports pasways and jets..............

Re: cns carb...OMFG ! beware!!!

then after the soapy was and blow out i decide i am going to inspect all the ports with a led flashlight ..... here is what i found....

the choke hole was drilled off center and strait through the casting into the top of the float bowl !!!!!!!!!!!!!!!!!!!!!!!!!!!! W T F !!!!!!!!!!!! no wonder it didnt work right !!!

so when i turned the choke on instead of drawing gas up through the tube that runs to the bottom of the bowl it sucked the air from the top of the chamber above the float giving the motor air instead of fuel !!!!! that suction of air from the choke was fed by the vent tube and caused neg preashure in the bowl causing gas to be sucked in from the float needle over flowng the bowl and leaking everwhere !!!!!!!!!


the light shining through in the first pic is from the hole the drilled throgh into the top of the float bowl !!! in the last pic i put a flashlight in the choke hole and you can see exactly where the hole in the roof of the chamber is !!!! the brass post is not even funtional because they missed the passage !!! it just pulls air from the top of the chamber over the float and it keeps getting iar fed to it by the vent tube and causes neg preasure and then suckes from the float boal needle and then floods the bowl ....

honestly i have never seen anything like this in my life WHERE IS QUALITY CONTROL ? HOW COULD THIS PASS!!!!

to fix this i have removed the choke cable and blocked off the choke with a bolt holding the spring and plug in place.

Re: cns carb...OMFG ! beware!!!

here is all the plastc i got out !!! just out of the carb !!!!!

Re: cns carb...OMFG ! beware!!!

this would have been a great carb if it wernt f ed up !!! now i have no choke ! and the only real thing to do to fix this would be to just get a real carb like a mikuni vm or a detoro no junk clones with crappy castings and misdrilled holes !!!! so i am looking at a 60$ part now, but i will run this one without the choke temporaraly until i get some cash to buy a real carb.

all those vent hoses surve no pourpose aside from sucking dirt in eather lol
i think they stuck them on there just so it would look cool to the uninformed ... average joe see's a carb with all kinds of bells and wistles and hoses and thinks wow thats must be high preformance lol but we all know a high preformance carb is nothing but a carb that meters fuel and air verry well and is very adjustabe and that is all !

Re: cns carb...OMFG ! beware!!!

now that this thing is together i have to readjust my air fuel mix and idle ... i hope with the choke blocked off and everything cleanned up i can get this tuned up right now !!!

Re: cns carb...OMFG ! beware!!!

ok got it all together and on the bike and test ran it wile tunning it ahhh damn it now it 4 strokes at all rpm's when not under load ! the air fuel mix i keep turning out 1/4 turn but its still doing it .... another few turns farther it will be all the way out and i still think it will 4 stroke,also my needle is non adjustable the clip has only one pos all the way up. should i order a few smaller main jets ? the stock one is not labled however so i do not know what size to order as i do not have a refrance point to go on lol

what size is the main jet in the cns carb on the grubee gt5 ???


on that note.... the bike even though its 4 stroking when not under load, is running a lot better and has a snappier throttle responce. it also pulls hills a little better than before. and runns a little bit faster but winds out at the top end.

Re: cns carb...OMFG ! beware!!!

wow man finaly after a week of tunning and soldering and drilling and resoldering and redrilling jets and adjusting floats and numurous plug chops at differant rps and throttle positions i fiiiiinaly have this thing tunned to the T !!!!! even without the choke i still managed to tune it pretty good. i got rid of all most all the 4 stroking .. wel i decided that i want some 4 stroking at cruise with no load, but uder even the slightest load or acseleration there is none and all is good thoughout the rpm and throttle range !

pics of stock plug from engine before i tore down the carb and tunned it and pics of the current plug after tune ! also pic of how i tunned my motor

just have to e mail them to myself from the phone

u know ... this carb if the quality were there ... would be a verry nice carb !!!! i have learned this cns carb inside out and i decided i like it, now i can easly tune it myself and i know where and when what jets come into play and how to adjust them to work together. even though the needle has no clip adjustments i have found that the air idle screw goes all the way up to almost half throttle anyway and the needle has a shorter duration than normal carbs before the main comes into play. it never realy needs to be adjusted because the air idle screw can cover most of the beginning of its range.

all in all i like the cns now ... probably only becaust i know it now and can adjust it and i bet would love a sha deltoro ! but money is tight and if i were to buy a new carb it would be a walbro !

ohh and this carb does not respond well to float bowl adjustments ! when adjusted way down it ran exactly the saame as before acsept at fll thottle for a long time it would runn out of gas by drainning the bowl, and at a high position it ran the same as before acsept when idleing it would overflow and leak out the vent hose. right in the middle and it wont run the bowl dry or overflow and seems to rn the same ... i dont thing you will get any leaning or richening out of this carb by flaot adjustments at least from my experiance.

just set it so you have a full bowl without overflow on lvl ground and you will be set. if it bogs wile at full throttle for a wile you need to raise it up to let more gas in .

Re: cns carb...OMFG ! beware!!!

ok here are the pics...........
as you can see the 3 prong plug was the one that came with the motor and was used wile the carb was run stock with the recomended 16:1 ratio lol its terrible !!! AND THEY CAPPED OFF THE CARB ADJUSTMENTS SO YOU CANT CHANGE IT LOL

the single prong plug is my current plug after pulling the cap of the air idle screw and tearing the carb down and rebuilding it and cleanning out the garbage that was in it.... nice brown color.

to get it tunned i marked a line on my throtttle for idle then marked a line for wide open then half throttle then 1/4 then 3/4, this way i can see where my throttle was wile my bike was running and properly tune the correct jets