Oil Tank Filling with Gas

[Liquid Blue]

Writing in for my buddy. He has an '05 Vector ER purchased used back in October. Definitely not stored with fuel stabilizer as had sat for at least (1) season and not started. Took carbs apart to clean, then started right up. He took out in yard (2) days ago and saw oil flowing out airbox breather. He checked the oil tank and it was full to top with mixture of oil and gas (verified oil qty was correct). Disassembled carbs again and did not find blockages. Needle valves, fuel pumps, or other? Thanks.

 

[jamesc]

absolutely, positively do not attempt to run or even crank an engine under such conditions. no matter what fix the problem before going any further with oil changes etc. i'm new to sledding but as you mentioned the most likely suspects would be the needle and seats and i "assume" the diaphragms in the fuel pumps are a possibility as well though i'm not certain i've never seen one apart.

pull the plugs, completely drain both oil tank and sump, oil filter removed and replaced. oil filters should always be filled with clean oil prior to installation. personally if it was my sled (i'm anal) i would try blowing it out some with compressed air, maybe throw a couple quarts of cheap light oil in the tank and crank it over a bit with the plugs out to flush the oil system then drain and replace the filter and oil.

 

[thrasher]

Don't know how gasoline could get into the oil tank like you described. Something sounds fishy. Is your friend familiar with Yammi 4-strokes? Did he put the sled on its left side with a full oil tank to fix something? Maybe previous owner or whoever thought oil tank was for two stroke and put 2-stroke oil in mixed with gas? Tank should not be full to the top either. As jamsec said, change oil and filter yourself first with cheap regular oil, run to flush engine and see what the problem is, and then change to proper oil.

 

[chrome]

I think I can help on this one. My buddy had an 05 vector, same exact symptoms started after he took to dealer to get carbs cleaned, they dunked the carbs in a solvent tank and one one piece, not exactly sure what it was, was displaced and fell in the tank, they put everything back together and it ran fine, except after 50 miles you could tell there was gas in with the oil as the dipstick was above full, we did an oil change and then started out again to find same situation. Took it to Meyer Yamaha and they took the carbs off found the missing part that allows gas to leak into oil, replaced it, put back together and problem solved, has ridden 5 k miles since this with no issues. Check to make sure all carb parts are intact. Good luck. Let us know what you find.

 

[woolyviper]

oil tank has a breather in the airbox, if you have a stuck needle valve and they puke gas into the airbox - the gas could get in the oil that way - i've seen stuck needle valves and they will move a lot of fuel thru the vents in the front of the carb - not only into the airbox but i've seen them fill the tops of the valves - which could cause big problems once it gets into the combustion chamber

 

[Liquid Blue]

Thanks guys. He found the problem. Stuck needle valve on the center carb. Now it's time to ride!