Black carbon on spark plug - 82 jet installed

[Exe]

Today I cleaned my spark plug, the stock one from the factory, at the 1000 km maintenance period.  The spark plug was black and I've been told that means it's running too rich.  The only modifications I have done to it have been a smooth boss drive and the 82 jet supplied by Kymco, which they recommend for a derestriction.  I attempted to adjust my mixture screw, so I removed the cap due to the new EPA laws (luckily it was installed wrong), but the screw head was gone and replaced with an almost semi-circle one, of which I don't have the tool for.  I find it quite ridiculous I can't adjust my own machines; I feel like a child attempting to bypass a child lock.  I'm not sure what to do next.

I run 93 octane fuel, adjusted my valves to 0.06 mm, changed oil, and clean air filter along with the spark plug today.

[blue]

sounds like you are doing good but the valves are. 0.04  not 0.06 adjust the carb and you should be fine.

[Exe]

sounds like you are doing good but the valves are. 0.04  not 0.06 adjust the carb and you should be fine.

For the 2012 models, the valves are 0.06 mm ± 0.02 mm.  I also can't adjust the carburetor due to the EPA restrictions without the proper tool.

[streido]

Check your engine oil level isnt too high. I had a similair issue a while ago and was messing around for days till i spotted i had slightly overfilled during servicing. Soon as i drained a little and cleaned up my plug i was fine again. Wish i had spotted it before i cut holes in my airbox to get more air in as i thought i was running rich too 

We live and learn.

[wordslinger]

I also can't adjust the carburetor due to the EPA restrictions without the proper tool.


..where are you, and could you post a pic of this carburetor??

 

..i'm very curious, as i've never heard of such a thing...

[Exe]

I also can't adjust the carburetor due to the EPA restrictions without the proper tool.


..where are you, and could you post a pic of this carburetor??

 

..i'm very curious, as i've never heard of such a thing...

All new carburetors sold in the U.S. for 50cc or below engines must follow the EPA federal laws that recently took place.  So, any new moped you buy made after the new laws took affect, basically now, will have flat screw heads for the float chamber and a plug over the mixture screw, which may or may not have a phillips screw head.  Another friend of mine bought a moped a bit after mine and his carburetor was completely locked down.  We had to take a power drill to the screws just to put a new jet in.  This is done because they want only the dealers adjusting the carburetor to avoid breaking the EPA federal emission laws.  For the new Kymco's, I believe 2012 and on, you will need a special D-shape screwdriver to adjust the mixture screw, like mine.  It's illegal to sell to the general public, as only dealers should have it, and carries I believe a $36,000 fine for violating the emission laws.  You can sill find them online easily though.

[REDKYMCO]

To my understanding if you are only changeing the smooth boss there was no need to have a larger jet as the smooth boss alone gives you 38mph approx and does not lead to running lean, there seems to be different dealers giving different advice. I know of A few ag50 owners whe have had the smooth boss only replaced and are running fine....

[Exe]

To my understanding if you are only changeing the smooth boss there was no need to have a larger jet as the smooth boss alone gives you 38mph approx and does not lead to running lean, there seems to be different dealers giving different advice. I know of A few ag50 owners whe have had the smooth boss only replaced and are running fine....

Kymco recommends a 82 jet for derestriction.  Plus, my scooter runs far better with it installed.  Though, I'm going with wordslinger that I overfilled my oil, because I could smell it in the air filter.  I made sure this time that it's not overfilled.

[wordslinger]

...i saw one of those carbs yesterday...idle mix screw not there...like, epoxied over..

...wowww..

..chinese scoot...idling like crap..only adjustment available is the idle speed screw..