2 stroke oil reserve tank over filling with fuel ???

[No more boats]

2000 OX 66 =250 hp - 2 stroke
yesterday , pulled boat , pulled drain plug
water coming out was clear , then oil was mixing with the water with a smell of gas coming out ?
Never had a problem with 2 stroke oil system

gas is returning & over filling 2 stroke external reservoir . ( reason for oil/ fuel in bilge ) tank was overfilled with oil & fuel coming from top and where tank is mounted it runs off into bilge
Engine oil tank had gas mixing also
Making a complete loop of the oil system
realize i can run 50 :1 oil mixture by passing but want everything working as it should
what would cause the fuel too come back too oil reserve then fill engine oil tank ?
oil pump ?
inside vst tank ? stuck float
check valve ?
this issue must have happened on return too port cause hour earlier my head was in bilge and everything was fine , I was off shore close too port

some thoughts is appreciated

 

[99yam40]

I have no idea how gas could be transfered to the oil system in an injected motor

 

[No more boats]

I agree with you ,
I have a retired marine mechanic buddy , he looked at it yesterday ,
He said this is a first ,
He feels its the check valve causing back flow ???
He said if you cant fix it , just by pass and run 50:1 directly , as a last resort but want it running as it should

 

[lelyyy]

It’s true—check valves tend to get stuck when they’re old. Might as well try swapping it out first; they’re not that pricey anyway.

I agree with you ,
I have a retired marine mechanic buddy , he looked at it yesterday ,
He said this is a first ,
He feels its the check valve causing back flow ???
He said if you cant fix it , just by pass and run 50:1 directly , as a last resort but want it running as it should

 

[No more boats]

2000
OX 66
2 stroke
250 HP

After a day on water removed drain plug , Smelt gas
Puddle of oil * gas, bilge ?
Axillary tank over filled with gas and traveled into bilge , ?
Opening reserve oil tank had a gas smell
Same with oil tank on engine

Months prior new Carter fuel pump in VST tank, filter , gasket .
Ran boat many times with no issue
This all happened weeks ago , started too find out WHY but had too go out of town Back on it now
Noticed ( don't know why ? ) put the black vent line from oil tank on one of the small nipples top of vst ??
Could have this caused no release and fuel too back up with no vent ??
As I said engine Ran fine many times . That day Temp was around 95 ,
Float got stuck ??
Check valve by oil pump ??
Thinking about adding two check valves at top of VST top , one for Oil & fuel
Any other ideas before I get back too fining out how this could happen ??
thanks

 

[No more boats]

2000
OX 66
2 stroke
250 HP

After a day on water removed drain plug , Smelt gas
Puddle of oil * gas, bilge ?
Axillary tank over filled with gas and traveled into bilge , ?
Opening reserve oil tank had a gas smell
Same with oil tank on engine

Months prior new Carter fuel pump in VST tank, filter , gasket .
Ran boat many times with no issue
This all happened weeks ago , started too find out WHY but had too go out of town Back on it now
Noticed ( don't know why ? ) put the black vent line from oil tank on one of the small nipples top of vst ??
Could have this caused no release and fuel too back up with no vent ??
As I said engine Ran fine many times . That day Temp was around 95 ,
Float got stuck ??
Check valve by oil pump ??
Thinking about adding two check valves at top of VST top , one for Oil & fuel
Any other ideas before I get back too fining out how this could happen ??
thanks

Just noticed a few responded from my last post , sorry I reposted , going too swap out check valves and make sure float is not stuck ,

 

[jbcurt00]

Just noticed a few responded from my last post ,

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