Df175 leaving behind oil or fuel sheen

[Cfishh]

Noticed the other day while warming up my Suzuki Df175 idling at the dock an oil or fuel slick behind the boat. Tilted the engine down today and left it for a few minutes before starting, nothing leaking there so I'd have to assume that eliminates the tilt/trim motors and lower unit gear oil plugs as the culrpit. Started it up and within a minute I noticed the slick again. This continued until the engine was shut down and for a few minutes after. This engine has been running perfectly fine so I'm stumped as to where or what the issue is. Took the cowling off and I'm almost positive it is a gasoline smell. Seems to be coming from either the mid section or lower but no signs underneath the cover. Any suggestions??? Thanks

[Harper]

Stuck float on the VST.. Fuel overflowing into the water via the VST overflow tube. Run the motor with the cover off, and look at the tube that comes out of the VST (if I recall correctly, it comes out of the top front of the VST, a foot or so long). It just dumps onto the outside of the motor under the cover.

[Cfishh]

Mike, thanks for the reply. If this is my issue, any idea how to fix this stuck float? Will running the engine a few more weeks like this be OK?

[Harper]

Not really okay. Against the law to knowingly pollute the waters in that fashion, for one thing. You need to open up the VST and determine the cause of the stuck float. It works very much like the float in a carburetor (not sure any young folks know of the carburetor, haha). But could be a worn needle, a failed float, no longer buoyant in the fuel, dirt in the needle seat, etc. But first check out the overflow like I suggested to ensure that that is the culprit. With the cover and possibly the driveshaft cowlings removed, you should be able to see the fuel coming out of the vent line with the engine running. That line is not really an "overflow line" and I am incorrect in calling it that. It's meant to be a vapor line, to vent vapors, not fuel. The only reason fuel would come out is the overfilling of the VST tank due to the float valve not shutting off the fuel intake when the fuel reaches the correct level..