More Engine Issues (1984 9.9 Evinrude)

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Oct 23, 2020
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Linwood NJ
After thinking I had the motor running flawlessly, I ran into another issue while out on the water the other day. After the motor started up the first pull I began to head out and while throttling up the motor it slowly began dying and stopped. I got it started easily enough but it didn’t run for long before dying again. Good thing I brought the oars :)

I can start it up as long as the choke is all the way out, and it idles with the choke all the way out; once I push the choke in and try to throttle up the motor slowly begins to die. I assumed this was likely due to a dirty carburetor, so I ordered a rebuild kit and took my carb out this afternoon; to my surprise it looked squeaky clean with no sign of fouling. The kit should be here tomorrow so I’ll switch everything out anyway but I can’t imagine that’s the issue. I was running the fuel/oil mixture a little rich (accidentally dumped about 8 extra ounces of oil into 6 gallons fuel) but after reading some opinions online it didn’t seem like this would cause an issue, and it ran about 4 gallons of this mix just fine.

Thanks in advance!
Everyone on here knows more than me but my first thought is a vacuum leak. If you get it running, then briefly block off the carb bore with your hand, see if the motor revs up and continues to run. If it does, there is a leak from somewhere and it may not be obvious. Intake, crankcase half, crankshaft seal etc. Anyway. Just my two cents worth.
Did you try pumping the bulb as it was bogging down? If you can manually pump the bulb to keep the carb bowl full and she runs fine then you know for sure that you have a fuel supply issue. The vacuum leaks already mentioned are certainly possible too but I would start at the tank and work my way downstream towards the carb first. You want to make sure your tank vent is open, tank pickup screen is clear, and hose connections are all tight. I've had air leaks in the quick connect between the cowling and the bulb line before and has been the most common issue for me, probably due to buying a cheap ebay/amazon connector instead of OEM. Generally fuel pumps are reliable but I did have a Johnson 15 where one of the check valves somehow came loose and rendered the pump useless. Anytime I get a new to me outboard, I always replace the fuel line from the pump to the carb with clear line and I add a small inline filter. That just helps diagnose problems a little quicker since if the lines/filter stay full of fuel and you have bogging issues you know you have an issue with the carb itself but if they are dry you have an issue upstream. And typically a small air leak in the line somewhere will still give you some flow but it will be reduced and probably have air bubbles in it.
Appreciate everyone’s feedback!

Today I received my new fuel pump in the mail along with some clear tubing to replace the black tubing to allow me to better troubleshoot. After replacing the fuel pump and priming the engine, I noticed the tubing was full of a milky colored liquid.

I disconnected the large fuel line and pumped fuel directly into a clear container. I was shocked to find all the fuel coming out was milky and cream colored, and that it has a bit of an alcohol smell rather than a regular gasoline smell. I suppose water has been intruding into my west marine fuel tank, which isn’t surprising considering how bad the **** thing swells in the heat.

At this point, I suppose I’ll start over with a new gas tank and fresh gas. I plan on cleaning the carb and changing the seals with the OMC kit and running the fresh gasoline through the new fuel pump. Anything else I should as a precautionary to prevent corrosion in the engine? Also, who has a recommendation for a good portable fuel tank? I know in the future I should store it in the shed, but I was worried the West marine one was going to explode one day with how bad it swelled in the heat so I left it outside in the elements (my fault).

Thanks for any input!


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Well.....that was definitely NOT an engine issue! Simple things first.

Now when you replace the gas in your tank remember that the engine carburetor, fuel lines, and the tank to engine line including the primer bulb will be full of that water with a bit of gas on top!!
Years ago, I had the same thing happen to me on a 9.9 Evinrude. I had the engine running at home with no problem. I took it out the next morning and as soon as I left the landing the engine started skipping and dying. I found out the gas I purchased for it that morning was bad gas. After getting fresh gas the motor ran fine. Lesson, just because you purchased gas that day does not mean it is good gas.

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