1997 rt 100 carb problems

[tylercharous]

hey im fixing a dirt bike for my friend.

it has been sitting for 4 years and i got it to start...barely

replaced 2 cycle oil and trans fluid and yes the oil pump works.

when i started it, it idled rough and shut down when the choke is off.

so i rebuilt the whole carb and cleaned it.

heres the problem, i can still get it started(have to adjust the carb screws a little bit to get it right)

i can get it to idle with the choke just barely on, but when i turn the choke off and rev it so it doesnt die, its like it revs on its own and automatically pins itself and redlines and only stops once you turn off the kill switch.

is there something wrong with the carb? or is it something worse?

ive never experienced this before, really strange. and it did the same thing when it was last ran approx. 4 years ago.

thanks.

[dondeere]

The only way it can rev high is to get air flow. Is the carb slide stuck open?

[tylercharous]

nope, it moves smoothly and never got stuck when i rebuilt it and played with it so i have no idea.

going to mess with it some more today, hopefully something will go right.

[tylercharous]

I may have figured out the problem so please help me out.

I read that when the needle above the float get stuck the air/fuel mixture goes crazy high.

here is what I found.

from what I have worked on so far(98 kx125, 85 and 86 dr100, 1986 yamaha 300&440 snowmobiles) all the needled in the bowl are attached to the float in some way, either 2 little clips hold it on or its top is spring loaded so it is forced to come down with the bowl when fuel is low.

in the carb for the rt100 there isn't anything connecting the needle to the bowl, just sits there.

should it be conected to the float?
do I need a whole new assembly or just the needle?

I figure cuz the bike will idle for 10sec, rev high real quick then die, or redline itself and I'm forced to either shut it off or pul the spark plug wire off when the switch fails.

please let me know if I'm right, thanks.

[dondeere]

If the needle is stuck closed it would cause a lean condition. Sounds like your on the right track.
.

[QuickMick]

if your motor is reving to the moon on its own, yes it has either a air leak or your throttle barrel is stuck open.
If your needle was shut then it would run out of fuel and wouldnt run very long. Yes the needle should be connected to the float via a small piece of wire that clips to the needle.

[wfsdno]

Hello, new person here with a 96 RT100.

Does anyone know the correct float setting for this bike?

Is the setting from the edge of the bowl, top of gasket or measured with gasket out and on inside rim of carb?

Thanks, and sorry for hijacking this thread.

Roger

[stenny]

Originally Posted by tylercharous

hey im fixing a dirt bike for my friend.

it has been sitting for 4 years and i got it to start...barely

replaced 2 cycle oil and trans fluid and yes the oil pump works.

when i started it, it idled rough and shut down when the choke is off.

so i rebuilt the whole carb and cleaned it.

heres the problem, i can still get it started(have to adjust the carb screws a little bit to get it right)

i can get it to idle with the choke just barely on, but when i turn the choke off and rev it so it doesnt die, its like it revs on its own and automatically pins itself and redlines and only stops once you turn off the kill switch.

is there something wrong with the carb? or is it something worse?

ive never experienced this before, really strange. and it did the same thing when it was last ran approx. 4 years ago.

thanks.

I am having similar issues but mine sounds like a diesel I had same thing and my float was getting hung up also I can smell the 2 stroke oil being burned so I think the oil pump is working and now it won't start