Fuel/oil mix leaking from crankcase vent tube 2004 DF50

[Sparky64]

Leaking fuel from valve cover tube into airintake

[Sparky64]

Gas going into crankcase, engine idles perfect, seems to happen around 2000 RPM

[Sparky64]

I was hoping someone out here has seen this issue before.

[Moonlighter]

VST likely blocked up. Clean out VST and reset float.

[Sparky64]

To be clear, it leaks from valve cover hose into air intake area. It has raised oil level in oil pan, so it getting fuel into motor.

[Sparky64]

Thanks for the reply Moonlighter. I was hoping it could be the low pressure fuel pump diaphram, a lot easier to work on.

[Sparky64]

How does a blocked VST dump fuel into motor?

[Moonlighter]

VST has a vent hose to take (normally) gas vapour away, and instead of venting to the atmosphere (due to emissions regulations) it is routed to the crankcase. But if the VST becomes contaminated and gets blocked up, it fills with fuel and then it runs out the vent hose into the crankcase.

This is a problem that often arises due to dirty fuel and/or the lack of a water separating fuel filter being positioned in the fuel line between tank and engine. If you don’t have one, you should get one fitted ASAP.

If you really want to receive informed responses, you would be best advised to provide more fullsome information explaining the issue, the history around it and what you have already done to address it.

[Sparky64]

Thank you again Moonlighter. I appreciate your getting back to me. I always use water separator filters on my boats. Ethanol free fuel is what I use as is recommended by Suzuki. After draining vst, no water in jar. I figure some small item at float needle. I will drain oil, rpl filter and reroute that vent hose to a catch can until fixed.

[Tides2]

Check for leaking diaphragm in mechanical fuel pump. - its the only access for fuel to get into oil sump. - easy to replace - i had same problem on 2007 df50