gas leaking

[redline7702]

My 02 cr 125 I have noticed that when I lean it over at about a 45 deg. angle gas is pouring out of one of the tubes coming off the carb.  Is this normal?

[William1]

Yes

[redline7702]

Thanks,

 

I figured so.  is it a safety thing to keep engine from flooding.  what is the reason it does this?  Does this mean every time im  riding and on a angle that gas is pouring out?

[Trailryder42]

The carb float bowl has an overflow tube. It's height in the bowl is just above the normal float level spec at where the fuel is shut off from entering the bowl and a constant predetermined level is maintained. The overflow tube is usually just a little offset to one side of center in the bowl. When you tilt the bike over, the fuel level covers the tube and is expelled.

 

If you ever find that the bike pisses all the time or when it's on the side stand, that's a good indicator either that some trash is caught in the fuel inlet needle, it needs replacing, or the float level is misadjusted, allowing too high a fuel level in the bowl.

 

Don't worry about it pissing fuel during your normal riding. Really, How often and how long are you at a 45* angle? Usually only when railing a corner at high speed, as railing a corner at that angle at low speed, you'd fall over.

 

Just be sure your float level is set to spec and call it good.

Edited February 25, 2016 by Trailryder42

[William1]

45 degrees is a lot.

 

Your carb has a ideal fuel level, maintained by the float. Think of a glass of water, filled to a inch of the top. You can tilt the glass and not will spill. Tilt it too far, some will spill (like your carb did through the vent hoses) However, with a running engine, at speed, the fuel being drawn in by the engine can often keep up with what might spill out the vents hoses so... no spill. Take that same glass of water and tilt it, this time on to your mouth and drink it. No spilling. Kind of a simple explanation.

 

The vent hoses do two things, The equalize air pressure in the carb float bowl and if the bike falls over, give another path for the gushing of fuel to take other than into your engine and hopelessly flooding it.

[redline7702]

Thanks for the input.  

 

My bike seems to run very well.  I have just recently noticed a noise once in the power band only in 4th or 5th gear.  hard to explain kinda like a vibration in the motor.  if you play with the throttle it goes away.  also seems to disappear after about 20 minutes of riding.  never heard this from any of my other 2strokes.  any ideas?

[William1]

If it goes away when the bike gets fully heated up, you are running it too hard too early. It takes 15 to 20 minutes for the bike to be completely up to operating temp. This is very important on a 2S.

[redline7702]

ok so I went riding yesterday for about 4 hrs.  the noise does not go away after it warms up. to more define when it makes the noise  is only in 4th and 5th gear right at the beginning of power band.  any ideas on what the noise could be.  sound like a girggle

[William1]

No idea. Take it to a local pro and let them listen.

[Trailryder42]

Borrow a GoPro camera and post a video of you riding while you're hearing the noise.

 

Could be anything. There may be a specific frequency vibration at those gear/engine rpm combos that some component on the bike is susceptible to. A cable, mud flap, plastic bodywork etc; could be chain slap.

Edited February 27, 2016 by Trailryder42

[ass]

When railing a corner the fuel wont spill from the overflow due to centrifugal force...try this take a half full glass of water and hold it by the top at arms lenght...spin in a circle real fast and notice how u can hold the glass on its side like you were pouring it out and all the liquid remains in the bottom. You can even spin it in a circle round and round at your side and even when completely upside down the water stays in....think about those guys in the circus that ride round in those lil ball cages with a girl in the middle...bike upside down girl not wet....from fuel anyway.

[Trailryder42]

When railing a corner the fuel wont spill from the overflow due to centrifugal force..

 

Good point, it most likely won't overflow from the lean angle of the bike. But if you haven't set a max float drop to your float travel and left it as comes from the factory ( which is often not set or set to allow way too much drop), that centrifugal force with force the float down into the fuel level, displacing it upwards toward the overflow vent.

[ass]

Good point, it most likely won't overflow from the lean angle of the bike. But if you haven't set a max float drop to your float travel and left it as comes from the factory ( which is often not set or set to allow way too much drop), that centrifugal force with force the float down into the fuel level, displacing it upwards toward the overflow vent.

I hadnt even thought of that....thats why i love this place...2 brains better than one and all.