03 tt-r 125 carb question

[jahames7]

hey fellas i just bought an 03 tt-r125 and i'm having trouble with the carb. when the fuel is turned on it seems to just run straight through the carb and drain out onto the floor. what causes that? i've taken the carb apart and cleaned out the float bowl. and where is the idle adjustment screw? where the adjustment screw is located on normal carbs it seems like this one wasn't machined and threaded for a idle adjustment. im puzzled by this carb so can yall point me in the right direction??

 

[2strokerfun]

Don't know about the idle screw on that bike, but the running gas is from your float needle and seat. Either clean them or replace them. When the gas raises your float, the needle should seal off the seat to prevent more gas from flowing in until the float drops again.

 

[Chili]

The fuel running through will likely be from the needle/seat being worn or having crud caught in it. The idle adjustment is on the left side of the carb part #8

http://www.bikebandit.com/houseofmo...torcycle-ttr125er-carburetor/o/m7723sch257049

This is a common problem for that bike, a little research will lead you to all sorts of threads on how to mod that bike and rejet the carb to make it run better.

 

[dirtbikerida63]

i had the same problem when i had my yz125. when the floats get pushed up it pushes air into into this black bubble thing and makes it expand and stops the gas from coming in. There more than likely dirt caught between the bubble and where the gas comes in making the gas continuously flow through it

 

[_JOE_]

i had the same problem when i had my yz125. when the floats get pushed up it pushes air into into this black bubble thing and makes it expand and stops the gas from coming in. There more than likely dirt caught between the bubble and where the gas comes in making the gas continuously flow through it

What? :whoa:

 

[_JOE_]

You need to take the float bowl back off and clean or replace #21. It's the float valve and seat. you should have seen the little tapered valve on the float tab when you took it apart. This peice and the seat it mates up to can corrode or jam a tiny peice of grit in between and cause leakage.

You should have an idle screw on the side of the carb. There may be a brass plug over the fuel screw on the bottom, #12.

 

[jahames7]

cleaning the float valve did the job. there are no leaks at all now thanks.

the problem now is that i can't get my bike to idle off the choke. off the choke its like the idle screw does nothing. if i have it choked i can adjust the idle and the bike will rev high and low but once i take it off the choke the idle screw has no effect on how the engine revs. is that normal?? what can i do to fix that?

 

[_JOE_]

Your pilot jet is probably clogged. For some reason these bikes have horrible issues with clogged jets and corroded choke plungers. It's a good idea to pull it off the bike and clean all the jets and passages in the carb very well a couple times a year. Use a light coat of wterproof grease on the choke plunger. If you turn the petcock off at the tank before you're done riding and run it out of gas it will help prevent the clogged jets and hard cold starting.