Fuel Overflow Problem

[CWLESQ]

I am a new member/long time lurker. Here is the issue. I purchased a '07 (581 miles) with a rusted gas tank. I used Caswell sealed the tank and cleaned the carbs. After putting the bike back together, I found gas pouring from the overflow tube. I pulled the carbs again to check the float height. It was set at 17 mm, however at this measurement the needle spring was halfway compressed. I put the bike back together, only to find that the same problem persists. Here are my questions: (1) It seems that the carbs need to be almost held completely sideways not to compress the needle spring. Is that correct? Does anyone have any pics of these measuring the float height so I can get the angle right? (2) The bike runs perfect when the the gas petcock is off. Any I chasing the right issue? Could this be a petcock problem? (3) When the fuel is pouring from the overflow tube, the exhaust is white. When the bike is running good with the petcock off, the exhaust is colorless. Thanks in advance. I searched the forum for any answer, but could not find a post and fix on point.

Chadd

[Motofool]

Welcome to our site, Chadd !!!

Check this:
http://faq.ninja250.org/wiki/How_do_..._the_floats%3F

If you adjust the floats properly and still see overflow, then one or both valves are leaking.

Sometimes the neoprene of the needle hardens, sometimes the aluminum seats have sediments or debris.

[CWLESQ]

Thanks Motofool. I will pull them again and adjust then advise. Ugh.

[Motofool]

You can gentle blow via a tube in order to check if the valves close for the proper position of the floats while the carbs are out.

You can also connect a transparent tube to the installed carbs, fill it with fuel and see if the column of height equivalent to the level inside the tank stays at the same level or not.

[CWLESQ]

Thanks for the help Motofool. The spring in the needle float was stuck. Problem solved.

[Motofool]

You are welcome, Chadd

[csmith12]

[n4mwd]

Sounds more like a petcock problem to me. See my blog below for simple instructions on testing it.

[MaxxVE]

Where is the spring in the float needle? It must be internal and that knob on top is actually a plunger that moves?

I'm having a similar problem but somehow I believe gas is overfilling the bowls and getting into the cylinders. I could just be paranoid but I turn my petcock to the off position when I'm about a half mile from home so it helps drain the bowls a bit.

I think I read that the excess fuel should drain out of the clear overflow hose between the carbs. Will that happen before flowing into the cylinder?

Sounds like a may need to pull the carbs again and set the float height and make sure the float needle spring plunger moves freely. (Sorry to steal the thread CWLESQ but it somewhat applies and I've attached a picture! )

[n4mwd]

If gas is running out of the petcock when the engine is off, then the petcock needs to be rebuilt. Turn petcock to RUN or ON, and then remove the large fuel line. If any gas comes out, then its bad. The float valves cannot cut the gas off completely.

If gas is leaking out of the bowl gasket, then you need a new bowl gasket. Don't use RTV or else it will gum up the works.

EDIT: See my blog below for more petcock info.

[MaxxVE]

Yeah, there is a drip every so often from the petcock while in the ON position with the engine off. I think I need to shim my carb needles as well so I'll have to have the tank off to get at those and that'll be a good time to rebuild the petcock as well.

[n4mwd]

Yep, it sounds like your petcock o-ring is bad. Be careful getting it out because the diaphragm is easily damaged.