Chinese bike problem, Lexmoto xtr 125cc

[DaB0B]

Hi all

I'm brand new to this forum and new to motorbikes, but not afraid to try and learn as i go, and not afraid to use a spanner!! seeking help on a Lexmoto XTR 125cc i recently bought.

Yes i bought a Chinese bike, you dont have to tell me im an idiot

When i bought i noticed that when i turned the handle bars from left to right, the revs would decrease or increase accordingly. No big deal i thought, throttle cable must need slackened, so i did, only to discover the bike wont idle now. So the previous owner must of being using tension on throttle cable to set the idle. Not so good

So next step i took after hunting web pages, was to adjust the engine idle at the carburetor, gave a small clockwise tweak to what i think is the idle speed control screw (highlighted in pics i added). Engine idle came up, great!! Next problem is that the engine sounds a bit sluggish, and when i pull the throttle back quickly the engine will cut out. After more web searching i believe this is because the engine is running rich?? So the next step is to lean out the engine??

This is where my problem is, if the screw i think it is, is actually the idle fuel mix (highlighted with red arrow in pics) then it is totally unaccessible, any one have any tips how to adjust this with out removing the carb??

Or if i am even looking at the correct screw??

The picture i have highlighted another screw with a blue arrow, this should be more easily accessed, is this infact the idle fuel mix screw? not the one i highlighted with the red arrow?

Any help would be greatly appreciated

Thanks

Bob

https://www.mychinamoto.com/forums/attachment.php?attachmentid=13954&d=1380920101

[nightshaddow]

you do in fact have the correct mixture screw but these as said are a pain to get to,

when i had the skyjet (same bike different stickers) i used to use a screwdriver bit from a power drill,

the best way to correct it in fairness was this

https://www.mypurerush.com/8bundle-packages-save-a-a-a/akuma-carburettors/mikuni-30mm-carb-pit-bike.html
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"WHAT DO YOU MEAN 100 MPH THATS IMPOSSIBLE Its chinese OFFICER."
Current rides CB 125 TDE(the next project) NS125RK ( now on the road ) CB125TDC (soon to be project 17) melody ( the nephews )

[P.]

Blue is float bowl drain.

Red is indeed the air screw.

Idle speed is correct

[DaB0B]

damn was hoping it was the other screw

guess ill just have to fiddle about with it some more, ive tryed long nose pliers but cant get the little bugger to turn

But with my fault finding am i on the right track? totally new to bikes, fast learning curve here with these Chinese machines

[bikenut]

:D you've done a brilliant job of cleaning that carb :D :D :D

if carb was removed and wrapped in clean rag, then very hot water was poured over the stuck screw, it may turn........

there is a possibility of distortion............

under that screw there may well be a spring, washer and o ring......so be carefull...about the o ring as if careless you may dislodge it and cut it and force a bit of it into the "hole" which will be a real pain to get out, if you take the screw out that is......

refitting would be screw held vertically with the "pin " sticking up, fit the spring, then the washer, then the o ring, then fit the lot to the carb.......

does your carb have an acceloration pump " squirt pump"....? to rid the flat spot or engine dying on quick throttle opening

see cmsnl for a similar carb exploded view or do lexmotor do a parts list and exploded views??
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nuts about bikes

[bikenut]

:D looking at your pics again that carb does have an acceloration pump ( squirt pump )...........which will squirt a small jet of raw fuel into the carb intake when the throttle is opened relaively quicky, but virtually no squirt when opened slowly, if its working properly that is.........

how is everything else such as air filter element and the needle on the throttle slide ( under the top screw top and spring etc ).......clip is on the middle notch for datum ( a starting point for full throttle adjustment...... ) ........

look at the spark plug colour guide on the "Bike running hot" thread by draco87 on the thread list.....

tried to copy and paste the guide but didnt happen........
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nuts about bikes

[Rogerborg]

Oh, bad luck.

No chance of getting at it with a thin electrical screwdriver? Can we see it in situ on the bike?

Check that the carb is secure on the inlet rubber and that there are no air leaks. Also, don't guess, diagnose - pop the plug out and check the colour, it could be leaning out rather than running rich. My Chinese fake-away came with the idle lean, presumably to scam emissions regs.
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