Still having issues with my 140cc lifan

[dsrt4]

I have a Lifan 140cc I have have had fits with ever since I bought it.
It came with a 24mm china mikuni and It ran like crap so it was suggested that I go to a 26mm carb.

I Bought a 26mm carb and it wasn't much better.

The Bike started and Idles fine but once you get out of first and into the pipe it just falls on its face. I have moved the needle up and down and it did not help. I then adjusted the carb and it did not help either.

I bought the engine new from tbolt usa as well as the bigger carb.

I have this engine on a Lifan ct70 clone that I had intentions of riding back and forth to work (6 miles each way) and I have ended up letting it sitting getting more and more frustrated with it.

Im close to putting the stupid 110cc back onto it. At least it ran.

Any Ideas?

[Blitz$M.Inc.$]

did you get a bigger diameter pipe?
is this the 140 with the 27/23 valve head?
off throttle is the air fuel screw, mid range is the clip
how does it run wot?
i have the same issue with my 160, the pipe that fits is too small and it like backlogs, not really sure how to explain it
so i cant even tune it till i rebend my other pipe or by a new one
my legal bike rolls 11 miles each way to work, its a blast, kinda shitty mileage tho

[dsrt4]

I did put on a bigger exhaust but that did not do a Dang thing but. Make it louder.

I am not sure about the valves. This is the iron jug 140 that has a all up shifting pattern

[Monster_Bike1780]

check your valves

[dsrt4]

That was one of the first things I tried a few months ago.
They are inspec.

[X7rocks]

If it falls flat on its face its due to there not being enough fuel.
Theres more to tuning then the clip itself. what main jets have you tryed...and what style 26mm carburator do you have.

[guruhelp]

While it might seem that richer is the way to go, I found that when my bike fell "flat on it's face" when the throttle was whacked open, it was because it was to RICH on the main jet.
TBotlUSA has some good tech pages for tuning your carb, but you may need to get at least a main jet kit, if not a pilot jet kit, too.
Vince, the owner is a pretty good guy and will answer the phone if you call during business hours, too! Not TOO many business owners that are that accessible!:yup:

[Blitz$M.Inc.$]

well my 22 carb ran fine till i went high comp then i had to get a true 26
i like to keep my carbs close to the size of the intake valve, any bigger and your just gonna splash gas on the valve, too small and it will run too hot and fade in power
running rich for a bit wont hurt your motor, running too lean will tho

[X7rocks]

Running to rich will just cuase a slight drown in HP since it cant really burn it all. but like you said it wont hurt the motor.