2006 ttr125le

I bought my wife a ttr125 and it has been leaking gasoline out of the float overflow tube. Even with the tank petcock off while the bike sits it slowly leaks. This causes the bike to be a pain to start after sitting as it's flooded. You can smell the fuel while I kick it to clean out the engine.

Today I pulled the carb and cleaned the float bowl and needle. I put it all back together and turned the fuel on. I waited a bit to let it prime and then fuel started dumping out of the over flow tube again. It started on the first crank with the e start and stopped leaking. I let it sit and warm up and revved it a little to see if it would leak and it didn't. So I took it around the backyard a couple of laps and checked again; pissing fuel from the overflow again.

Any ideas? I was told the bike sat for awhile without use. Everything looks good in the float bowl.

Are you sure that the float is moving correctly so it shuts off the fuel? Do you definitely know that the fuel tap is working and is off when it says it's off? Just a few things to check. Good luck!

The float was moving like normal and the needle fully seated and has no wear.

The fuel petcock does leak a very very tiny amount when in the off position but there is no pressure compared to how fast and steady it comes out of the overflow tube.

test the fuel petcock first.  replace as needed. 

 

second check with Yamaha to see if there is an updated needle/seat for the carb.  they updated a LOT of their models due to ethanol fuel eating the needle/seat assemblies.

 

also replace the fuel line from the petcock to carb as ethanol can eat the line causing particles to block the needle from closing all the way. 

Needle and seat is what shuts the fuel off in the carb. Normally you don't have to shut the petcock to keep the carb from leaking out the overflow.

 

Needle and seat is dirty / damaged. Could also be the adjustment tang on the float keeping the needle open.

the issues is when the bike is leaned over on the kickstand for storage, the floats are not level thus the needle will not have the full pressure to fully seat the needle.  So yes during storage, you need to check that the petcock does stop the fuel flow in the off position and/or store the bike in a stand to keep it level

Good point about it leaning and messing with the float while stored. I'll put it on the stand tonight and see if it still leaks. I'll take the petcock off and clean as well.

Like I said the needle and seat are in perfect condition. The bike has maybe 10 hours on it since new. It sat forever without use.

It only happens when on the kickstand?

I'd have to say adjustment tang then. That or it's parked on very uneven ground or your kickstand is badly bent.

Normally you don't have to shut the petcock to put the bike on a kickstand.

I'll check when it's standing straight up as even after riding I would leave it running and put the kickstand down so I can look under it. The kickstand isn't bent and I did check on even ground.

So I left it on a stand and can see the fuel is still leaking. I've had bikes not leak even with the fuel turned on for an extended amount of time.

Is there a way to adjust the float level? I couldn't find anything in the manual.

I'll pull the carb again as well as the fuel petcock this weekend.

So I left it on a stand and can see the fuel is still leaking. I've had bikes not leak even with the fuel turned on for an extended amount of time.

Is there a way to adjust the float level? I couldn't find anything in the manual.

I'll pull the carb again as well as the fuel petcock this weekend.

There is a thin peice of metal that holds the needle and connects it to the float. You could try slightlt bending it up to make the needle seat quicker.

Make sure to not bend it a lot. Just a LITTLE.

I adjusted the float and cleaned the inside of the petcock. Still leaks. I'm going to try and replace the petcock since that should be cutting off fuel while it's just sitting there.

Having a working petcock is a good idea but still shouldn't need it to stop the fuel when taking a break on the trail.

Did you unscrew the seat under the needle?

Take the carb off and remove the float needle/seat. Get some carb cleaner and douche. Use a q-tip in the seat. That varnish is real sticky but carb cleaner seems to melt it away.

If I remember correctly the choke system can bypass the needle/seat on some carbs so also look there.

Oh. That black tip on the needle is made of rubber so be careful with it. Ethanol can break down that rubber tip. Inspect it close.

I ended up replacing the fuel petcock and found some debris under the needle seat after pulling it out. Cleaned it out and now everything is working perfectly. 

 

Thanks guys. 

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