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slowxr

Fuel flowing out of overflow tube.

14 posts in this topic

This is a brand new 650. The first 50 miles I had no problems but my second weekend is when this problem developed. When I pull to a stop, lean the bike on the kick stand, fuel pours out of the overflow tube. If I stand the bike straight up, the leaking stops. The bike runs good and I didn't have any of the out of adjustment float symptoms I've experienced on other bikes.

Also, it didn't do it everytime I put it on the kick stand. I think it leaked about 70% of the time.

Any idea's?

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Either a vent tube is blocked, the float is sticking or it needs to be lowered a bit.

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How likely is it that the float would be out of adjustment from the factory?

A blocked vent tube would sure be an easy fix. What should I look for? Dirt or a kink in a tube?

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I don't know why the float leavel set so high. Mine lost half a tank on the stand when I first got it while I was helping another rider. Bend the floats down some and it will be fixed, it doesn't take much. 2mm

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That probably explains why I ran out of gas too!

I'll give that a shot. Thanks

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I am at work so, I don't have (or remember) the messurement.

Ask Eric at:

http://xr650r.us/

I am running the mikuni now.

Make sure you adjust your valves at 600 miles.

Having a BRP is a lot of fun you can tinker and tinker, making it faster and fast. When you get to holes in the air filter cover and such you'll see it goes on and on. This week it's new braided brake lines. I am going to rap my header with the heat rap next. Had that on my old XR600. I have not modifide the engine and it is the fastest stock engine Oinker I have been on yet. I ride with a guy now and then that has the HRC Upgrade and that's fast. There was another guy that let me race him and then trade bikes and race again and he had just a cam. That was fast also, but, not as much as both the piston and cam setup. My big goal with this bike is to get the bigger valve setup, port poslish the head (intake, Exhaust and inside of head) and cam. Then later 680 setup. I think the 710 setup will be to much if that is possible. To much is never enough inless it shortens the life or makes the engine less reliable. A squeeling Oinker is a happy Oinker. But, it sure makes my face hurt, with that ear to ear grin I get stwisting the ear on the BRP.

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Hey man, check the float needle seat. Mine got stuck and it poured fuel out the overflow. Took it apart, and a white residue had built up on the needle seat, causing the rubber needle NOT to seat properly. I used a q-tip with berrymans on it to clean off that residue. The problem was fixed.

OF course there are many things that could cause your problem, but this is worth checking also.

Good luck with it.

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I had the same thing happen to me, all I had to do was to open the carb bleeder screw and flush some gas thru, probably had some residue in the needle seat, haven't had a problem since.

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I lowered the float by 2mm and it's still draining. If I park the bike on a flat and level area, it doesn't drain. If I park it on a slight angle(kick stand side)the gas overflows and keeps flowing till I either stand the bike up straight or shut the gas off.

The manual states that the float should be set at 16mm. When I checked it yesterday it was right at 16mm. How much lower can I safely run the bowl?

Any other possibilities?

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The last straw with my stock carb was the same problem you are having. I fixed it with a TM40 Mikuni pumper. I gave the carb to a pal with a 650L and he took it to the local Honda dealer and the head mechanic figured it out. He replaced the needle and seat.

After riding with the Mikuni I'm sorry not to have made this mod earlier, the stock carb isn't worth the trouble.

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Hmmm....

If you've checked everything else, then double check to make make sure your fuel tank vent is working. Have you ever left a plastic fuel jug with the vent closed outside on a warm day? You'll notice that it expands as it gets warmer. If your fuel tank isn't vented and things started to warm up, the fuel tank may pressurize and force the fuel through the needle/seat. The fuel sloshing around by itself from riding might just be enough to pressurize the tank to the point where it causes a problem like this.

The fuel system in our carb works similar to a toilets ball/[@#$%&!] mechanism (very simple). As the fuel level in the float bowl rises, the float itself rises higher, thus pushing it's other end with the float needle downward (like a teeter totter) to shut off the supply of fuel. Lowering the float causes the float needle to seal quicker so there's a lower fuel level inside the bowl.

If the needle isn't seating due to a seat problem or crud stuck in there, then it won't shut off the fuel supply and fuel will leak out. If the float itself isn't floating due to a leak or damage, then it won't shut off the supply of fuel. If the pressure inside the carb is greater than atmospheric pressure due to a plugged vent in the fuel system (carb or fuel tank), then pressure may overcome the needle/seat and fuel may be forced through that junction. There's only so many things that will causes this problem and it's a matter of eliminating them one by one.

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Slowxr,

I hope you are still checking this forum. I just posted with the same problem. After my second float adjustment, it stopped, but now it won't idle well. Maybe just crap in the carb. Did you solve your problem?

Gary :)

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I lowered the float by 2mm and it's still draining. If I park the bike on a flat and level area, it doesn't drain. If I park it on a slight angle(kick stand side)the gas overflows and keeps flowing till I either stand the bike up straight or shut the gas off.

The manual states that the float should be set at 16mm. When I checked it yesterday it was right at 16mm. How much lower can I safely run the bowl?

Any other possibilities?

50 miles? Take that thing back to the Dealer and let them sort it out!

Honda really stands behind these bikes. My new one had a weird "break"; the upper boss (that holds one of the two bolts) holding the cage around the front sprocket busted in half. This of course means a new lower case, not a trivial warranty expense for Honda. The Honda zone guy took one look (digital pics I emailed) and said, "Never seen that before, the bike looks clean and not abused- no problem, it's covered". Now if the parts would just come, but that's another story...

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