Green Fuel Problem

Hi Guys, I am new to this site I hope you can help me out. My engine is a 1994 200 hp Black Max.

I've had this problem earlier this season and after a quick fix I was taught for the problem I can now explain it better. This only happens when I let my boat sit for more than two weeks.

As before I went to start my O/B engine, when I went to pump the primer bulb and found that it was already hard. I tried to start the engine without success and I knew at this point what I needed to do. I unscrewed both drain plugs out of all three carbs. As I did this the fuel that was in the carbs flow out much thicker than fuel and dark green, like Simple Green only darker. After this I noticed that the fuel at the bottom of my 10 micron water separator filter in it's clear bowl was dark green too. I drained the filter as well as all of the fuel in the primer bulb line. The first bit of fuel that came out of the primer line was also thick and dark green too. I did take some of the fuel from the filter that I drained an set it aside to see if there was any water in it and there wasn't. I then sprayed carb cleaner into each tube in each barrel to flush any gelled fuel that remained in the carbs. After all of this I was then able to start and run my engine.

I know this is related to the ethanol in the fuel I buy. How can I stop this? I don't want to have to deal with this when I go striper fishing and it is 20?.

Re: Green Fuel Problem

The dark green part could simply be the oil which would be normal. I use Quicksilver oil which turns the fuel dark green.
The thick part is the part I would worry about.
It almost sounds like you're getting oil but no gas.
Is it an oil injected model?

Re: Green Fuel Problem

I am presuming that you use a non-green 2 cycle oil? If so, the green sounds like a by product of water+ Ethanol in the gasoline. Can you drain the gas tank? Is the boat on a trailer? if so, block up the trailer tongue, and remove the gas tank fuel level sender. Stick a siphon hose into the bottom most part of the tank and suck out the fuel into a clear container. The water and gel should settle to the bottom of the container. The good gas can be reused.

Re: Green Fuel Problem

You might also check your gas tank vent to be sure it is clear.

Re: Green Fuel Problem

I think Mthieme is on to it.

Is the "green" just 2 cycle oil? If it is, the trouble would be that the check valve that supplies crankcase pressure to the on board oil tank isn't letting off after shutdown like it is supposed to. The oil is slowly forced through the engine tank, then the oil injection pump into the fuel system. When the carbs are full, it then will try to go back toward the tank. Add a slightly weak check valve in the primer bulb, and you get a line full of oil.

It usually isn't that extreme, but it's plausible.

2 cycle oil is oily. real slippery.
green from corrosion (usually from copper or brass) is usually gritty and grimy.

After you get it running, shut it down. Five to ten minutes later crack the fill cap on the oil tank in the boat. It should not be under pressure.


hope it helps
John