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Post by Blueboy5000 on Jul 14, 2011 7:33:19 GMT -5
Hi Dawgs! I'm new to the forums here and I have question:
I own a 2002 Kymco Yup 50cc 2-stroke. Up until now it has been a great bike. I loaned it to my brother and he wound up trying to adjust the mixture himself, leaving it stinking of gas when it's running. I looked all over the internet and I can't find a diagram of the carburetor for a Kymco anywhere.
From what I can tell this is almost the same bike as the Kymco Sting 50. Does anyone know which screws are which on the carb? I would like to know the proper method to adjust the mixture and idle and cannot find a picture explaining it anywhere.
Thanks guys!
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Post by Blueboy5000 on Jul 16, 2011 8:25:13 GMT -5
Really? No one knows which screws are which or how to set the mixture/idle on a 2t 50cc Kymco?
Well can't say I'm surprised as I can't find any picture or diagram of the carb anywhere.
Thanks for your help Dawgs, or rather, your total lack of any help.
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Post by mainepeace on Jul 16, 2011 10:35:10 GMT -5
There are HUNDREDS of variations of scooter models out there. Perhaps nobody here has a 2002, which is probably why nobody has responded yet. We're not ignoring you! Typically someone will answer if they have an answer, and if there isn't a response yet, nobody knows.
Post a pic of both sides of your carb and I'm sure someone will chime in.
Greg
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Post by Blueboy5000 on Jul 16, 2011 14:35:26 GMT -5
Okay. here is a pic of the carb Attachments:
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Post by lbo on Jul 16, 2011 19:40:40 GMT -5
That carb looks like the one on my Kymco Super 9, a Keihin 14mm.
The screw on the bottom is to drain the float bowl, make sure that is closed or tightened all the way.
The "throttle stop screw" is the one directly above the float bowl screw, the "air screw" is the "+" looking screw to the left.
The starting poing for the air screw would be ~3/4 to 1 turn out, the throttle stop screw adjusts your idle.
From the service manual for my engine (same or similar looking carb as yours)
AIR SCREW ADJUSTMENT
Turn the air screw clockwise until it seats
lightly and back it to the specification given.
Air Screw Opening:
SH10DA: 1_ ± _ turns
Start the engine and turn the air screw in or
out slowly to obtain the highest engine
speed.
Turn the throttle stop screw to obtain the
specified idle speed.
Idle Speed:
SH10DA: 2000±100rpm
Slightly increase the engine speed and make
sure that the engine does not miss or run
erratic.
If the adjustment of the air screw within the
range of ±_ turn makes no difference to the
engine performance, check other related
items.
Hope that helps.
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Post by edfr on Jul 16, 2011 21:12:00 GMT -5
The Screw on the Left with the + is your FUEL RATIO adjustment it controls how much Fuel comes in. IF that screw was on the RIGHT SIDE by the Air Filter then it would be a AIR RATIO screw which controls how much AIR comes in. LESS AIR-RICHER, MORE AIR=LEANER.
The MIddle Screw is your IDLE ADJUSTMENT screw Clockwise Raises the Idle Counter CLockwise Lowers your Idle.
Your Fuel Ratio Screw works just like the CVK carbs COUNTER CLOCKWISE more Fuel CLOCKWISE LESS FUEL.
Lefty
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Post by lbo on Jul 16, 2011 21:50:33 GMT -5
The Screw on the Left with the + is your FUEL RATIO adjustment it controls how much Fuel comes in. IF that screw was on the RIGHT SIDE by the Air Filter then it would be a AIR RATIO screw which controls how much AIR comes in. LESS AIR-RICHER, MORE AIR=LEANER. Yeah I guess technically it is a "fuel" screw and not an "air" screw............. Kymco calls it an air screw. |
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Post by mainepeace on Jul 17, 2011 0:02:09 GMT -5
See the love blueboy? We're all here to help.
Greg
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Post by Blueboy5000 on Jul 18, 2011 6:01:14 GMT -5
Thank you very much guys. I simply seated the "+" screw and backed it out one complete turn, then started the bike, and turned the other screw (idle I supposed) until I got it to not stall, then turned the "+" out slowly (in 1/4 turns at a time) until I got the highest rpms, then I turned the idle screw till I got a good idle.
I took it out for a 20 mile ride and I am please to say the bogging is gone and all the power is back, and there is no stink of unburned gas. After I let it cool down I checked the plug and it is a pleasant light coffee color. I do believe you guys nailed the adjustment!
Thanks Dawgs!
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Post by lbo on Jul 18, 2011 7:13:35 GMT -5
Thank you very much guys. I simply seated the "+" screw and backed it out one complete turn, then started the bike, and turned the other screw (idle I supposed) until I got it to not stall, then turned the "+" out slowly (in 1/4 turns at a time) until I got the highest rpms, then I turned the idle screw till I got a good idle. I took it out for a 20 mile ride and I am please to say the bogging is gone and all the power is back, and there is no stink of unburned gas. After I let it cool down I checked the plug and it is a pleasant light coffee color. I do believe you guys nailed the adjustment! Thanks Dawgs! Good to hear. |
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Post by edfr on Jul 18, 2011 12:43:04 GMT -5
They don't call me the Carb Wiszard for nothing. Many just go and buy a new Carb when not needed. If the few parts on the carb that have rubber are still in tact all it takes is a good cleaning AND THAT INCLUDES the Passages most just clean the Jets and not the Passages and the cleaning may not have done squat. Got to clean out the Passages and make sure when spraying into the holes you see spray coming out from the EXITS of the passages then you know your passages are clean.
Lefty
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