Gas/oil mix dripping onto floor.

I have a82 xj750 seca. I just rebuilt the carbs. I installed them, started bike with a little choke and holy crap it started! When i installed them i did not hook up air box, and #3 carb hose. With in 4-5 minutes oil/gas mix started to hit the floor. I shut bike off. looked over carbs and its connections. no leak. When i pulled the airbox apart there is moisture on the bottom(air filter removed). I started bike and watched inside airbox. I could see misty/smoke comming from the hole for the crankcase hose. when i put finger on hole pressure would build up quickly. my questions are as follows..
1. Is that normal?
2. There is a possiblity there is a quart too much oil in motor. could this cause the issue discribed?
3.should i compleatly and corectly hook up airbox, and hose from #3 to the gas valve, then see what it does? Or is there some major problem?

Oh i have checked valve clearance they are just within specs.

 

The #3 carb hose runs the vacuum petcock, and I'm assuming you are running the bike on "PRI" Prime, which means you are suspect to draining gasoline into the motor, via a leaky needle/seat, then down the intake, sneaking past the rings on a piston, and into the crankcase, diluting the engine oil.

You feel pressure on the crankcase breather in the airbox due to the boiling gas in the oil.

It's normal if things aren't working right. :roll:

You have a judgement call to make - whether you have a few ounces of gas in your oil or quarts - - whether you just burn it off, or do an oil change.

You should have wet-set your carbs and seen then if the floats were working correctly, you also need to "flow-test" your petcock on "ON" by sucking on the hose and collecting the gas which is free-flowing like a Russian Race Horse.

 

I did a clear container float level test. all float levels are good. the gas tank is not even on the bike. Im using a fuel bottle. I do know i need to hook up the syncpro, then use a color tune plug. the bike does idle ,but not very good. but it does idle. when i throttle up a little it starts sputtering and poping. Guessing because of need of fine tuning mentioned above. Just wondering if the oil level being 1 quart high, and the crankcase not being vented properly,(via aircleaner box hooked up properly) if that could case the issue im havig? Remember the airbox is not connected, either is the #3 vac hose that does go to the tank petcock.

 

One quart too much oil will definitely cause some "pumping" but if it's also mixed with gas, you have a float issue.

Maybe you weren't precise enough with the adjustment (it's only a 3mm tolerance which isn't much) or fuel is leaking past the needle valve seats.

 

1. Since you do not have the petcock hooked up, and you're running off of an auxiliary supply--the fuel supply will be running constantly unless you put a manual shut-off valve on it. Check your crank case and see if you smell gas in there.

2. I'm not convinced there is any problem based on your description, other than that you don't have everything put back together yet. there's gonna be some fuel vapor at the carbs, there's gonna be oil vapor at the vent tube. Without the airbox and filter hooked up, you're not going to have the correct flow of air, so stuff is going to be blowing around. Hook everything up, go for a little ride and THEN see what it looks like. If you think you have too much oil, put the bike on the center stand and check the level in the window.

3. If you dont have a petcock hooked up, make sure that the pulse tube nipple is capped otherwise you get a lean draw there which can cause popping/sputtering etc......

4. It doesn't matter which intake boot you use for the pulse tube. Vacuum is vacuum and it's present at all four carbs. It will be pretty much the same at each one since you BALANCED THE VACUUM of the carbs. Again, it does NOT matter what cyl the pulse tube is connected to.


Hook everything up correctly, then go for a short ride. See what things are like then..........

Dave

 

thanks guys ill look into both recomendations. If anyone can think of anything else please post.

 

ok looks like there is gas in the crank case. =/ I removed the filler cap, and smelled gas. On my auxilary tank there is a shut off valve. but it is only off or on. So the only thing i can think of is, a stuck needle or float allowing to much gas in one of the cylinders. then leaking into case. I think before i try anything else out i need to do oil change. the sight glass on case is fully black. Im sure the extra quart and then fuel has got it over full. could be why i get a little white smoke out one exhaust. Guess its back to square one. Pull the carbs, set up on bench and check bowl levels using a clear bowl. :cry:

 

Check the float levels using a piece of clear tubing attached to the drain ports like the book says and see what happens. If you can't get all the drain screws free, then "rotate" one or two good bowl(s) down the line.