I rebuilt my carb thanks to suggestions from good people on here and now I have full throttle But...when I rev it up a few times it will blast black smoke out the exhaust and it doesnt want to idle on its own. It also seems to just be running rough while I keep it running.

I have adjusted the mix screw and tried it at every 1/4 turn from 3/4 to 1 1/2 turns.

it is also difficult to start and slow to respond, must feather the throttle.

If anyone has suggestions for this I would love to here them.

 

Fiche Parts

 

Yo may look at this parts breakdown of an carb like yours....Every company dont want you to see there carb part like this, BUT you look at photo number 9 this is the jet block and it has to oring under it that will wear an have flats spots or cut up orings which will cause your problem....rich mixture at idle....it causes fuel to dump in the throat of carb around the block an makes the engine runs rich because the excess fuel...you cannot adjust this out. So you will have to be very careful in removing the number 7 screws..they have loctite on threads an real easy to break off.So I turn screw real slow about an 1/4 turn in and out until screw starts moving out better, if you turn an screw to fast it heat up an breaks off. When you get these screws out replaced the orings with the exact same size....The other one that I have foundt to replace them is an honda oring...I have the part number at shop...but will be afew day before I can get it for you..NO honda dont have this type on in carbs...BUT after years of working professionally on these things I measured oring an got in an honda oring i.d. book an looked up this oring..been using it for over 30 years an works great...all carb with this jet block uses this size oring...But Im sure an good auto part store with an oring assortment get match up some for...take the block with you when you go....Again please be real careful in removing them screw. Just go real slow..turn in and out bout an 1/4 turn at a time... I dont put loctite back on the ones that I have replaced I have never had them to back out, its has an star washer under screw to loc the head were it want turn or back out...I hope this helps.. Its always works for me....Good Luck

 

Also put oil on orings when putting block back in carb.Make sure you match the little hole in the bottom of block with the carb....

 

You are the best...Thank you for all your time and info... I will give it a shot

 

Care & Feeding Of The Keihin Carb

This is a great link to the Keihin CVK carb on my machine.
I think it will be handy to anyone with this carb.

On the 1st page of the article it shows a pic of needle jet and collar, what Im not sure of is if I put the collar back in right, so I am going to pull that apart again to verify its in right. I know it has a small hole on one end and larger hole on the other but on rebuild it fell out and I dont know which way it came out !

 

The big goes up. It shouls also be beveled an little on the inside...

 

I pulled it apart again to verify and it was ok, put carb back on, fired up, ran a little rough, kept it running till warm then headed down the road, after 1/4 mile it made it to 25mph while I babied the throttle. on the way back I hit 30 and I am used to this running at 54...it revs good with a little sputtering until I put it under a load....it died when I tried to put it in reverse and would not start again so pushed it back into the garage and there it sits!!!!!!