Too much oil

[dbersuch]

What could cause so much oil to build up in the vapor separator on a 200XRIEFI that the engine will not start? It will fire and try to start but won't stay running.

[Eagle One]

Oil Pump maybe it actually mixes oil into the fuel line right before the VST, Might have a check valve bad or some linkage off as the pump goes wide open if the linkage come loose.

[j_martin]

About 3 minutes after you shut down, loosen the cap on the boat oil tank and see if there's pressure there. If there is, the bleed part of the check valve feeding it is plugged.

Valve is forward, starboard low with a hose on it.

[dbersuch]

Thanks, I'll check. You're talking about the main tank in the boat, not the small tank on the motor?

[j_martin]

Thanks, I'll check. You're talking about the main tank in the boat, not the small tank on the motor?

Yep. The valve in question supplies a couple of pounds of crankcase pressure to the oil tank to force the oil to the reservoir on the engine. It's supposed to let it bleed off in fairly short order after shutdown. If it doesn't the pressure slowly forces oil past the now stopped oil pump and it accumulates in the fuel system, either carb or EFI.

[dbersuch]

It did still have quite a bit of pressure several minutes after shutting off the engine. Removed the check valve and could blow through it with no problem from the motor side toward the tank. Could not blow backward through the check at all. Need to replace the check valve you think?

[j_martin]

It should "leak" back slowly. You might not be able to notice it with the lip lock test. I'd replace it, as it shows the symptoms of bleed back failure.

[j_martin]

Did you get it fixed?

[dbersuch]

Took the boat to the lake yesterday and tank still had pressure in it two hours after shutting off the engine. Need to order a bleeder. Engine was 500 to 600 rpm less than normal at WOT. Could it be getting too much oil at full throttle and preventing the engine from revving to the normal RPM?

[dbersuch]

New valve fixed the tank pressure problem. Motor will run up to its normal rpm of 5800-5900 at WOT but 10 or 15 seconds later will lose 400 - 500 rpm. Doesn't seem to miss or run rough, just slows down. If you slow down to 3000 rpm for a few minutes and then go back to WOT it runs up to normal rpm for a few seconds and then slows back down.

[bobthebuilder]

Pre Mix the fuel and remove that oil injection mess before you blow up your engine.. I get a couple every year blown from oil injection failure in my shop......