Motor Ran Rough, Flooded? Water in gas?

C

CDory23

New member
I was camping the last couple days on my 22 Classic Cruiser with twin Yamaha 40's. I rebuilt the carbs and increased jet size because of previous issues with these motors many know about. I have taken the boat out many times and its ran great but I had a strange issue happen when I took it out and started the port motor this trip.

I primed the bulb to the port motor and it didnt seem to have too much pressure so I pumped it quite a bit around 7x until I could feel pressure in the bulb.

When I started the engine it wouldn't start initially and i could barely get it to run extremely rough and knocking with the throttle speed all the way up. I went out and stayed close to the marina motoring off the starboard motor which was running fine. I tried to start it a couple hours later and same symptoms-it would run in neutral with throttle high extremely rough and would die as soon as I put it into gear to try to get propulsion from it.

The next morning I launched and figured I'd try to start it to see what happens and it started right up and sounded great and ran great all day.

I"m thinking. Did I potentially flood it that badly where it needed to rest that long? Maybe I should have just kept running it rough until it cleared itself out when it was having the symptoms.

Maybe I had water in the racor filter/fuel water seperator and when I pumped gas at that velocity through the bulb it took some of the water with it and that was causing the engine to run so rough?

Any ideas?
 
You should not flood the carb with just pumping the bulb--but if you over choked it, then that might cause flooding. I tend to be spare on the choke, especially when it is not that cold. Often the outboards need minimal choke.

The Racor filters do have Aquabloc technology. The filters will detiorate with time, and should be replaced each year. The 110 series (smallest flow) will still handle 35 gallons an hour.

I have seen water get by a Racor--maybe the filter was old. But if there is significant water, it should show up in the bowl of the filter (drain before each time you run the boat--not necessarily every day, but at least once a week or a cruise, or after fill ups.

My guess, is that there was some material in the fuel line--maybe after the filter? Was it non ethanol fuel? How old are the fuel lines? When was the Racor filter changed?

I always carry at least 2 extra filter elements for the Racor. Replace the element each year.
 
Everything in the fuel system is practically brand new. Fuel lines, bulbs, Filter etc.. I replaced everything when I rebuilt the carbs a month ago. I'm in California and use 87 so roughly 10% ethanol I believe. I also add mercury fuel stabilizer on every fill up and the gas was fresh-got it on the way there and filled up a nearly empty tank.

I did not drain the water seperator bowl, and rarely do.
 
Chances are, you had a partially somewhat stuck float on one of your carbs. My twin 45s have done that before. Once the float comes free, they run perfect again.
 
Interesting, that sounds like that may be it. Maybe too much pressure in the system or the velocity of gas entering the carbs caused the float to get stuck.

If this happens in the future any way of curing it besides just waiting it out?
 
T.R. Bauer":2facqmx4 said:
Chances are, you had a partially somewhat stuck float on one of your carbs. My twin 45s have done that before. Once the float comes free, they run perfect again.
Click to expand...

I would agree. Stuck float and gas kept being pumped into the carb, basically, flooding the engine continuously.
 
CDory23":22smkcac said:
Everything in the fuel system is practically brand new. Fuel lines, bulbs, Filter etc.. I replaced everything when I rebuilt the carbs a month ago. I'm in California and use 87 so roughly 10% ethanol I believe. I also add mercury fuel stabilizer on every fill up and the gas was fresh-got it on the way there and filled up a nearly empty tank.

I did not drain the water separator bowl, and rarely do.
Click to expand...

Any chance that the tanks at the filling station were just filled, or were being filled as you filled your tanks. (I've heard it is a good practice to not get gas if the delivery tank truck is delivering fuel, or did recently. -- It can stir up sediment in the holding tanks.)

Just a thought. Your filters should take care of that, but if there is moisture in those tanks it will stir that up as well.

Harvey
SleepyC :moon

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