Gas In Crankcase

[BOYZSBLUE]

GOOD DAY ALL, CHECKED MY OIL LEVEL LAST NIGHT BECAUSE I CHANGED OIL A FEW DAYS AGO, SMELLED GAS . WHEN I BOUGHT BIKE IT RAN, TURNED OFF ONE DAY TO GET A SODA AND IT WOULDN'T START. NO SPARK, FIXED THAT PROBLEM, NOTICE # CYL HEADER PIPE NOT AS HOT AS REST, TRIPLE CARB CLEANING WAS DONE AT THIS TIME ,EVERYTHING WAS FINE, BIKE RUNNING GREAT. BIKE STILL RUNS GREAT EXCEPT FOR GAS IN CRANKCASE. BIKE HAD GAS LINES GOING STRAIGHT TO CARBS, AND THAT'S THE WAY IT IS NOW. I TURN GAS OFF WHEN NOT RUNNING, FLOATS WERE SET TO 23MM, BUT GOING TO RECHECK SATURDAY, AND THE SHUT OFF VALVES WEREN'T LEAKING WHEN I REDID CARBS. COULD THERE BE ANYTHING I MISSED OR WHERE SHOUD I GO LOOKING FOR THIS PROBLEM . THOUGHT I COVERED ALL THE BASES BUT I GUESS I DIDN'T. THANKS FOR ANY HELP GUYS TO MAKE THE PAIN EASIER.

[mro]

Gas In Crankcase, BUMMER

As you may have read here about others that have had same problem,..... your float needle(s) are leaking, and if significant amount of fuel in crank case pet cock(s) leaking too



mro
btw
That's a good reason to use "in-line" fuel filters.
Seems filters on pet cocks let large enough particals get by to make float needles leak.

[mro]

BTW

Have a tank I'm going to be using soon. Has stuff rattiling around in it.

Will remove pet cocks and fuel cap etc.. Flush out with water hose and then dry with heat gun. If looks bad in there will wind up coating tank too.


mro

[BOYZSBLUE]

MRO

IS THAT THE ONLY WAY GAS CAN GET INTO CRANKCASE ?

[prometheus578]

"The only way."

Float needles not sealing properly.(needle or float problem. Can happen when running. )
Faulty petcock staying open and the gas eventually overcomes the seal on the needles.(can happen when bike is not running)
Carb bowl vents are plugged, and trapped air raises atmospheric pressure in the bowl and the floats wont rise properly.
Seal around needle seat leaks.

[dwain61]

Check your petcocks

I have seen the vacume diaphram in these petcocks tear and leak fuel down directly into the carb boots via the vacume line. Take a peek and see if thats what is happening. Pull off your vacume lines and see if they have gas in them or smell strongly of gas. Hey it happened to me! Good luck

[dragxs11]

food for thought

Most likely, thats the cast about the float needles leaking overnight. Some other issues that could happen are floats themselves filling up with gas....which would make it foul a plug real quick, and second, if your fuel stop diaphram(octopus) has been removed, the pressure in the gas tank could force fuel into the carbs.... from what I've seen, this only causes hard starts after a break from riding. But float needle leakage is a very common issue.

[BOYZSBLUE]

what i found

i got back to my leak problem this weekend. pulled the carbs to check what you all said , but everything looked ok until i noticed that the # 3 carb float looked a little funny. it wobbled on the pin shaft. doing top cats test to see , yes it was leaking, the copper insert on the float was worn so bad on one side that it would wobble and stick. replaced float and cool no more gas leak. then all hell broke loose. had bike sitting in driveway , gas tank turned around on seat area and hooked up doing final adjustments. got it run like a swiss watch again, took break to get a sandwhich. in the house i heae a bang like metal on concrete. looked out the window and what do i see.... my step- son pulled into the drive and bumped my babby just enough to drop it off the center stand and crash.big dent in gas tank, busted alt. case, foot peg rubber torn off. god...love those children.... 75ft driveway and he had to pull right up to the bike!!!! what do you do....??? alot of thoughts ran thru my head. at work right now will post pics later so you all can laugh. i had to or i would have killed him!!! looking for a alt case cover now it's not the stock case cover, changed with the parts bike motor, my alt was melted so i switched... i think it 's from an xj i don't know.. got to work will post later when things slow down