2005 Mercury 90 hp 2 stroke oil backflowing into fuel separator

Robjabi

Recruit
Joined
Apr 17, 2009
Messages
3
The motor sat for 2 months and when I went to run it I noticed blue gas at the bottom of the fuel water separator. Got the engine to sort of run by constantly depressing the primer button on the motor. I know bad. The motor will die immediately if I open the throttle and give it gas. Things I have replaced to date, new primer bulb, rebuilt the fuel pump, replace the hose to the fuel pump from engine. Thought that would fix it, No. Oil pump looks good no leaks? Carbs were rebuilt last year and the engine was starting and running strong all summer. When I replaced the primer bulb it dripped 2 stroke oil? Don't know where to go now? Anyone had this issue before?
 

airshot

Vice Admiral
Joined
Jul 22, 2008
Messages
5,168
While my motor runs great with no issues the oil mix draining back thru the system is normal. Mine has a clear fuel filter in the fuel line and I noticed blue gas in that filter. As the motor sits, the fuel slowly drains back thru the line...basic physics, liquid flowing to the lowest point in the system... I now unplug the fuel line when I am done with my boat and loading it on the trailer. No more blue gas in the filter !!! As far as your motor issues...sounds like a clogged carb, for starters run some Sea Foam thru it if possible to try and clean the system. I always use a fuel stabilizer in all my toys that dont get used on a regular basis, and never have had fuel/ fuel system issues....so far !!!
 
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