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Ok, I found the air /fuel mixture screw on the bottom front of the carb, just below the manifold... Ok now, how in the world do you adjust it if you have to remove the carb?? Does anyone know? Or do you just remove it, turn it to a direction and then install it and see what happens??? That would be a big pain in the butt.. Can anyone suggest how to do this... Temps here just began dropping dramatically at night so if it's cold air that's a problem then I can fix the old carb and keep the new one as a spare... Oh yeah, after reading the air/fuel adjustment tutorial in the tech section...I see that you should only adjust it if you are having problems at low speeds... I'm only bogging out when I cruise at 65+.... Any thoughts?

Do these carbs have an Air/Fuel Mixture screw as seen on the other carb??? I've also ordered some high quality vacuum lines (I was using goodyear fuel lines) and will be connecting the vacuum lines as you instructed on an earlier posting / diagram.. I will hook the top port of the maniford to the fuel pump alone and then all the other crap to the other port.. Hopefully this will make a difference also. I've also been thinking that the cold air outside 50 degrees and sometimes dropping to 40 degrees could be causing my engine to bog?? I work graves so I mostly run the scooter at night... It gets a little cooler here in the desert about this time of the year (live in AZ)..

Okay, I think I figured it out...again....lol..... I just looked at the tech section and was just curious about the spark plug area.. Maybe at high rpm's my coil wasn't working.. So I took the bike apart and took the coil off the plug... I had an extra plug laying around and hooked it up to see if I saw a spark.. I saw a spark for a split second and then nothing... Cranked it again and same thing... I played around at the coil connectors and all was tight and looked pretty damn good... But here it is, I was tugging at the coil just above where the cap goes over the plug and all of a sudden with the slightest and I mean slightest tug...it separated.. I looked at the wire that came out of the plug and all the little gold colored wires looked as if they separated a long time ago!!! I gues it was just connected with a little pressure and when I would cruise at 65mph + it would not be a good connection... So Jr or anyone else, could this have been giving me the problem??? I go back to day one with the scoot when it had 0 miles on it... I remember doing a PDI and replacing the plug, I'm pretty sure that I didn't tug the cap off the plug by the cap, instead by the wire leading to the cap... This is where I probably began separating it... Because I do recall that in the beginning, after cruising several miles, I would get a slight loss of throttle response but not as bad as it is today... And after replacing the next spark plug, I'm sure I pulled the wire again trying to remove the cap from the plug...thus separating it some more and throttle response / power was being lost even greater at cruising speeds... So, If this makes sense to anyone please let me know... I'm going to order a new coil.. Jr, do you know of a place to order one for the Linhai version?? I've seen some for the CF version and they look the same, would that work?? Thanks guys for all your help on everything... At least now I know how to completely take apart the scoot in no time!! lol....

Just a thought, after reading several postings of other topics related to the carb, I saw a picture of one of JR's postings of a carb... I noticed on the side of the gas port of the carb, just below the enricher, there was a plastic or rubber cover on one of the ports... I looked at mine and did not see that, just an exposed brass port... Is there supposed to be a cover on it?? While searching for new carbs, I also noticed there was something covering that port.. What is it for and does it need to be covered?? I can't remember if it ever had one on it to begin with and maybe it fell off... Anyway, please let me know what this port is for and if it should be covered.. Thanks for the help and I'm going to try the gas cap technique tomorrow..

Okay guys I'm back to square one!!!

My scooter remains losing what seems to be fuel at 60+ mph... I'm mean really lose fuel!!! I'll be cruising for a bit and all of a sudden, while I'm still holding the throttle, it'll just stop accelerating and bogg all the way down to the point it seems like there is nothing coming from the throttle pull... Here's what I've done this week and still no good results:
-Installed Mikuni fuel pump
-Replaced all fuel and air lines (twice in 3 months - just to be sure.
-Disassembled Carb and soaked it in Carb cleaner for 24 hours.
-Removed Fuel tank and cleaned it completely out.
-Another valve job.
-Added seafoam to fuel.....
-Adjusted float in Carb
-Adjusted fuel / Idle for Carb

All this and still absolutely no difference!!!
Is it possible that I just have a bad Carb??? Has anyone ever experienced this and tried all the above but still got nothing??

My wife is ready to kill me because of the time and money I keep spending on the scoot... But she knows I love it and it is a great fuel saver, when it's running, to and from work (76 miles round trip)...

Now for those of you that don't know, I have a JCL MP250A with the Linhai engine..

Also, if anyone has purchased a decent carb please let me know where you got it from... I don't want to buy a cheap carb because chances are I'll have the same problem in the future..

Oh yeah, silly me never measured the carb size that I need.. Can someone tell me the correct size I need... Thanks for all your help guys... Scoot currently has 5300 on speedo...

Took apart the carb and cleaned it... Wasn't too dirty at all.. Also checked measurement on float and it was already at 19mm... After putting it all back together, took it for a spin... I cruised a while at 75, longer than normal then it suddenly started again!!! I'm thinking that I'll just change the fuel pump because this is what I've seen others have issues with when it came to losing fuel delivery at high RPM's... It seems that I lose fuel delivery up and down hills... Also, I live in AZ - not too many hills in the valley.... Lots of flat ground.. If I order the Mikuni single fuel pump, is there any adjustment I have to make on it before installing or do I just take it out of packaging and connect it the way the old pump was... Anyone know?? I'm not sure and any help would be appreciated.. Thanks everyone!!! Oh yeah, now that I'm thinking about it.... There is one thing that I changed recently and if I really think about it - my troubles began from that point... I recently replaced the spark plug with one that was originally in the scooter (NGK DR8EA)... However, when I first got the scooter, I replaced the original spark plug and only used (NGK D8EA) - no resistor... So basically, after adding 4,000 miles, I went back to using the original recommended spark plug.. Is it possible, that the change of spark plug could cause this issue??? Just a thought...

Hello everyone!! Well I'm back with another problem.. For starters, let me say that I have a 2007 JCL MP250A (linhai version)... My scoot currently has 4500 miles on the speedo and was wondering if anyone has had there engine bogged down after cruising about 70 mph for more than 5 minutes??? I can't figure out what the problem is... My temperature guage is also floating and it never did that before... When I come to a complete stop, it'll stop floating (at least a little) but I'm not sure if it's giving an accurate reading. As I cruise on the highway, the fan is always on so I assume that that is working properly... I just don't know, is the engine bogging down because it's getting worked to hard and starting to overheat or is it something else?? I checked coolant level and it is where its supposed to be. Just recently (200 miles ago) did a valve adjustment and changed the spark plug with a standard NGK DR8EA + an oil change with Mobil 1 synthetic motorcycle oil 10W40... If anyone knows what the problem is please let me know.. My engine doesn't cut off at all it just boggs down after cruising 70 mph+ for more than five minutes... The bogging is getting worse everyday and I'm fearing that soon my engine will just die. I ride my scoot daily to work and the round trip totals 77 miles (all highway). Thanks for the help!!! Hope everyone is doing better than me!!