Oil sucked from tank into engine. Why???

[George G]

My 1996 Speedster worked 100 % last week yet yesterday it sucked all the oil from oil tank through and into the right engine in about 5 minutes of running. Yikes!

I had oil in the hull but that was from it pumping throught the carb and out through the air cleaner cover. I pulled the air cleaner off and there was oil right up to the choke butterflies.

Some kind of check valve stuck open?

 

[jords]

sounds like the oil pump is stuck or the cable broke off it, the outside of the pump gets pretty gumed up after the years. Reach down and move the oil pump arm and see if it springs back. If it doesn't looks like it needs a cleaning or your pump is gone.

 

[phough5757]

Seal Problem.

Sounds like a seal on the crankshaft has failed.
I hate to say it... Time for a rebuild.

 

[seadoodude1]

I agree, bad crank seals on rotary valve engine is about the only way for that much oil to leak into crankcase.