Motorcycle Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
I have a 4 stroke 125cc, it wouldnt start without choke and died without revs (wouldnt idle) so i cleaned out the carb and removed and cleaned the jets then reassembled it. After that it didnt start at all, a few hours later it started fine and idled but a little high so i turned it down using the screw on the side of the carb. The next day it was just clicking so i charged the battery today and after 4-5 seconds of holding down the electric start it started and idled perfectly but now if i throttle quickly from idle it cuts out (doesnt cut out if i throttle slowly). Any help would be great because im very new to this and im out of ideas.
 

·
Gone
Joined
·
23,907 Posts
It not uncommon to need to use the choke to start. Most carbed bikes need to use the choke with a cold engine.

Are you allowing the engine to warm to operating temperature with the choke on before attempting to operate the throttle?
 

·
Ghost in the machine
Joined
·
2,857 Posts
If it continues when it is warmed up (as Dods asked), then you will probably have to remove and re-clean the carb again. Remember that there more places to clean than just the jets. Most folks fail to clean the idle jet "port" completely, as it is very small and requires something the size of thread or small fishing line to pass thru it.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #4
it still has the same problem when warmed up, when i cleaned the carb i removed both jets and flushed through with carb cleaner and used a guitar string to make sure the jets were clear. a guy at my work says it sounds like its 'bogging down' so i need to adjust the screw on the side of the carb. does this sound right? any advice would be great.
 

·
Ghost in the machine
Joined
·
2,857 Posts
Did you re-install the air mix screw back to it's original position (turns ) after you cleaned it? It should be approx 1-1/2 turns out.
 

·
Registered
Joined
·
24 Posts
There should be a screw for idle rpm on the side of the carb, try turning it so the idle is stable. Does it cut out when you have choke on and give throttle fast? If it does, it might run too lean. And if it seems to be running lean, check the spark plug, remove it and see if it's white it's running lean, if it's like coffee with milk it's running well, if it's black it's running rich.
 
1 - 6 of 6 Posts
Top