Author Topic: Left bike on PRI, all gas drained out? (Read 4139 times)

silverbandit96 · « **on:** December 17, 2005, 06:04:19 PM »

I've been having a loto f trouble getting my bike running, and last weekend I accidentally left the bike on Prime. I came into the carage thsi weekend and it smelled like gas. THe gas tank was empty, probably had 3 gallons in it. Engine would not crank over (too much gas). Oil is totally overfilled (too much gas), and I pulled the plug for the airbox tube and probably 1/2 a gallon of gas came out there. This tells me a couple things. 1, I'm an idiot. 2, I need to pull the plugs, drain the oil, take apart teh carbs, and let it sit. 3, Something is wrong with the needles/floats in the carb? Seems to me 3 gallons should not have leaked out taht quickly, I must have a needle not seating properly somewhere, but when I took apart my carburetors, everything looked fine. Any ideas on how I can tell what caused this problem? Obviously whatever caused this is what is making it very difficult to start.

Red01 · « **Reply #1 on:** December 17, 2005, 09:33:10 PM »

It has to be something in the float system. Most likely, the float needle & seat, but I have seen a case of a sunk float once. It was obvious once the float was removed and you could hear gas sloshing around inside the float. This was on a brass float equipped set of carbs. Funny thing was you could move the floats every which way and gas wouldn't leak out. Not visibly anyway. Closer inspection of the floats revealed they had tiny stress cracks all over the place and fuel had been slowly leaching in thru those tiny cracks.

ray nielsen · « **Reply #2 on:** December 20, 2005, 11:38:08 AM »

If the bike was on the sidestand the angle might allow a float to be open just a bit.

Just a thought.

Red01 · « **Reply #3 on:** December 20, 2005, 10:08:25 PM »

I disagree.

Each carb float has two float chambers. If you tilt the bike, the float chamber on the lower side will move (or try to) even higher, so shut-off is maintained.

Kickstart · « **Reply #4 on:** December 27, 2005, 07:02:25 PM »

Hi

Had this happen with my 1200. Parked the bike at about 7pm, 9am the following morning 3/4 of the tank of fuel had gone through the carbs and into the engine / airbox.

Took the carbs off and cleaned out the needle valves but found nothing wrong there, but the problem never reoccured.

All the best

Keith

silverbandit96 · « **Reply #5 on:** December 28, 2005, 12:25:37 PM »

Well right now I have the carbs off the bike and the float bowl covers off. Everything seems fine, all floats are moving freely, The needle valves look fine. I took off the jets to clean, they seem to be in 2 parts, a smaller part that takes a flathead fits into a larger part that needs a 5/16ish wrench. I just took the whole assembly out and shot some carb cleaner into it and stuck it back on for each carb. Anything else I should take a look at while carbs are off?

Daytona · « **Reply #6 on:** December 28, 2005, 01:22:45 PM »

Just a shot in the dark! Could this be a result from a full tank (say just fueled and gas has expanded from eng heat?) bike on side stand allowing float pivot to bind? There is a reason they use the vacuum petcock on bikes! Its been a problem for a while! It would seem some one in the know would have found the reason! Or asked say the Mikuni folks...

silverbandit96 · « **Reply #7 on:** December 28, 2005, 02:03:02 PM »

No, that isn't likely, because the tank is vented, the bike wasn't running, and the entire tank drained. It is something in the carbs for sure. I did notice when pulling off the carbs that a bunch of gas came out between the number one carb and the intake manifold, so something for sure is wrong with carb #1 and I can't see anything. I hate to put the carbs back on and have the same problem because the carbs are a huge pain to take on and off.

Daytona · « **Reply #8 on:** December 28, 2005, 02:19:14 PM »

Oh well just chalk it up to Bad "F" "M"!!! Your vacuum hose that opens your petcock wouldn't happen to be on #1 carb would it? Most are on #3. By the way your tank venting is done by the springs and seal under your gas cap and will allow a bit of press to build before venting! The drain hole under the cap on the recess ridge only drains water/gas etc out of the recess area through your tank! If your hose is crimped or kinked and water can't drain & freezes it will split the pipe in your tank, allowing gas to run out from tank when water thaws!!! You seem to be having some bad/strange things happening to you, so just thought i'd throw that @ YA!!!!!!

Red01 · « **Reply #9 on:** December 30, 2005, 04:05:34 PM »

Quote from: "daytona"

Your vacuum hose that opens your petcock wouldn't happen to be on #1 carb would it? Most are on #3.

The B6 & B12 should be tapping the #4 carb.
Not that it makes any difference since the other three carbs cap this vacuum port anyway.