I have a 1990 banshee atv I went to drain the oil just bought the bike and when I open the plug there was no oil it was gas in the gears that came out from bottom what do you think is wrong.

SOURCE: 2009 650 Classic: Does not stay in gear, problem

Wish I could come up with a line of B.S. as good as their service department does. You have a slightly bent shift fork. Tell the jerks to fix it. It is a problem, it is not right, and it is covered under warranty. Tell them you really don't want to get creamed when the bike pops out of gear and doesn't want to go back into gear as a cement truck is coming at you. If you let them stall you until the warranty runs out it will cost you around $1400.00 to get it fixed. Contact the Regional manager for Yamaha ASAP. Google "Yamaha Motor Corporation" http://www.yamaha-motor.com/
What I am afraid will happen is that the dealer will do the repair and install a new shift fork then tell you they could not find anything wrong so you now owe them the cash because Yamaha will not stand the repair cost for a non-existent problem. Send Yamaha a certified letter as to your concerns and insist someone other than the dealer inspect the bike to confirm the problem. Keep a copy of the letter and the postal receipt. Is there another dealer in the area?

The diagram below shows how a shift fork moves a slider gear left and right to change gears. A slightly bent shift fork would not let the slider gear "dogs" fully engage into 1st gear.

A “very helpful” rating for this answer? Thanks!

SOURCE: banshee running wide open after a couple of revs

The problem with vents is that a vent can get plugged and lessen or completely kill the flow of fuel. They will not make an engine rev wildly. Your banshee has standard carbs. The throttle cables may be routed incorrectly, pinching or stretching the cables. Remove the air filters. Look inside the carbs. Do the slides move freely up and down when the throttle is twisted? In the diagram below note the junction tube on the throttle cabel. The cable can stick at inside the tube. Is the connector hose between the carbs in place? Also, there is a switch on top of the carb. This can go haywire also. Odd that the problem was not present before they cleaned the carbs.
Can I get a “very helpful” rating on this answer?

SOURCE: oil change on my 1990 fzr yamaha 1000

20/50 shouold be fine oil drain plug is under the belly pan

SOURCE: Went to change the oil on my 2002 electra glide ...nadda oil

are you sure you didnt drain the primary case oil they usually hold a little less than a quart.. dont run it until you make sure or you could burn clutch and primary chain up.

SOURCE: clutch doesn't engage until bike gets hot

this is the same with all 4 strokes. they all need to heat up before you can ride them, but this is not a problem.