2002 Kymco yup 50 Barn Find

[jmmc]

OK... totally confident in what is required.  Found a decent How To for the same carb and its pretty straightforward.  not too complex at all.   Sound is bad with the wind, but I get it. I can total get that accomplished.
  I suspect it will be clean as I have faith the guy who did clean it, did a good job.  Wish I would have come here first but the goal was to get this off MyPlate.  Now its not a rush. just get it done...and done right. 

[Kansas kymco]

I do not know a lot about the two stroke motors and how the oil is regulated.  Just telling you the issues I had with the two scooters I bought that sat for years. If you purchase another carburetor it will have to be of the same design for everything to work correctly.  It's possible that even though you had the carburetor cleaned contaminates from the fuel system could have clogged some of the passages again.

[dan v.]

That's a decent video about the carb cleaning.  I am surprised that he didn't take the straw from the carb cleaner and put it into the holes to clean the passages after the jets were removed.  It will not hurt - blow the carb cleaner into any holes you see.

My Bet and Win had 158 miles on it when I bought it at 14 years old.  It didn't run for crap.  I found out that whomever "cleaned" the carb before left out the washer and O-ring, and some other little parts  (that your carb doesn't have).  Don't assume that whomever had done work on the scoot before has done it correctly.....

[scooterfan]

You can also just strip the carb as indicated at the video, remove the small metal clip on the carburetor needle, and submerge all carb components except the small needle clip in white vinegar for 24 hours. The white vinegar will dissolve all gunk inside the the channels and after 24 hours you can just use an air compressor to finally blow out the remaining vinegar or possible remaining gunk inside the channels.

We used this method to clean out clogged carburetors at my previous job and it worked perfectly.
Just remember not to submerge the needle clip in vinegar - on certain carbs the metal clips get destroyed within less than 24 hours by vinegar completely.

[jmmc]

quick note. I received my Service Manual and its actually pretty decent. I was worried when I went to some of the Free ones on line with crude drawings and such. This will be a help to me and a plus for whoever gets to own this little beauty. Probably not a lot of 18 year old scooters out there. especially with 150 miles (not Km's) on them.
I have an all day conference Saturday, so It'll probably be next week before I can get back to it.  Time changes so a little time after work will help. 
Just wanted to stay engaged so you did not think I have given up or such... 

[Kansas kymco]

Thanks for the update.  Let us know how it goes.

[jmmc]

I'm back.. Saturdays got eaten up.  I got brave and removed and dissembled the carb. Its fairly simple as it applies to moving parts etc.  I did make a mistake.  I went and purchased parts cleaner in an aerosol can instead of Carb cleaner which seemed to be more for cleaning it in place? The cleaner did a good job and I will say that guy I paid to clean the carb obviously did not disassemble it. The jet that has the multiple sets of tiny holes offset from one another in the main jet area was clogged.  Took some fine wire and pulled out some green crud. Blew parts cleaner through it from both sides so its clean.  My problem was the parts cleaner.  The throttle stop screw that has an O-ring … the parts cleaner swelled it and when I was reassembling I pinched it and as I was trying to recover from that in backing it out.
The parts cleaner by this time was eating the plastic handle on my screwdriver so … huge flub on my part.

SO... no idea where to get that O-ring save for finding a store that sells or has a broad selection of sizes, Maybe the scooter store has them?  Or..... being as it seems to be a bottomed out insertion I am confident I could Teflon tape that groove for the o-ring to be air tight

So aside from that, I think I'll be in a better place with a clean carb.  Thoughts on O-Ring? 

[Kansas kymco]

Would a dealer or parts supply house have a carburetor rebuild kit for the carburetor with the correct parts?

[souzamoto]

Here's a diagram of the carb
Looks like your Oring is not a separate piece and comes with the idle screw.
Try your local ACE Hardware or auto parts store
CJS

[Stig / Major Tom]

Lowe's hardware drawers.
Stig

[stuo]

I did some tinkering on two strokes. The oil is either injected, in which case there is a separate oil tank...or it's premixed. If it's premixed you need to find out the correct ratio (shop or owner's manual or try 40/1, using two stroke oil.) The carbs on two strokes are touchy, jets and passageways must be very clean, air box and air filter must be stock, float level must be right on, the air/fuel mixture ratio is critical. If the plug is wet, it's flooding, if dry and black it's getting too much oil. Two strokes show some blue exhaust smoke (oil) even when running correctly. My guess, it's flooding.

[jeeves]

I did some tinkering on two strokes. The oil is either injected, in which case there is a separate oil tank...or it's premixed. If it's premixed you need to find out the correct ratio (shop or owner's manual or try 40/1, using two stroke oil.) The carbs on two strokes are touchy, jets and passageways must be very clean, air box and air filter must be stock, float level must be right on, the air/fuel mixture ratio is critical. If the plug is wet, it's flooding, if dry and black it's getting too much oil. Two strokes show some blue exhaust smoke (oil) even when running correctly. My guess, it's flooding.

If there is a "oil" cap under the seat close to the fuel cap then the scoot mixes it by itself. The more the throttle is open the more oil it mixes with the fuel.
On my wife's Vespa 50 the throttle cable is connected to the oil opening cable (pardon my English), probably the same or similar on most 2 stroke 50ccm machines.

Sent from my Redmi 4 using Tapatalk

[skandoe]

Hi, here is the carburetor workshop manual for the YUP 50. I hope this will help if you still need it.

[skandoe]

Here is the oil pump set up for the YUP 50