'02 9.9 Merc. Big foot - flooding problem

[schrof]

Problem:

In a years' time I've had to rebuild or clean the carb. 4 times because the motor starts to flood out. Gas will poor out the top of the carb when the fuel line is attached and flood itself out. If I detach the fuel hose, engine will run normal, no gas spewing out top of carb until out of gas. I can keep it running by re-attaching fuel hose for about 5 seconds but if left attached any longer, engine will flood out again, spewing gas out the top of carb.

I've had 2 carb replacement kits installed. After the 3rd time, I spoke to Merc. they believe its the gas in Illinois, clogging needle valve slightly or something w/float. I can't find anything in the carb or filter inside carb. when cleaned. The float works fine. Merc. told me that I don't have to get a replacement kit, just clean the few parts and reinstall them. I've done that with success, but its going to be an issue one time on tourny day. I have a friend with a non big foot '01 that has done the same thing over and over.

I know this is a long shot, but I'm wondering if it has anything to do with the kicker in the up position while trailering or running. I don't run the engine out of gas at the end of the day, anything to do with this?

Anyone else have similar problem and is there a remedy?

[dppeter]

I have an '01 15 hp Merc 4-stroke. I have the same problem over the past year except the problem is only after the initial startup after a couple weeks of non-use. I have been able to tap the float bowl with the fuel line attached and the overflow stops. I have never stored the motor in an upright position. Have always used Sea-Foam in my gas. After dis-assemblying the carb and making sure it is clean, I will now try running it out of gas after each use, (only when I won't be using it for a couple of weeks). I even open up the drain screw on the float bowl to insure no gas is left. I am hoping this procedure will help my problem. The flooding problem sure is upsetting.

[perchjerker]

I have the same motor as you guys. But I am lucky, I dont have that problem.

Schrof, when you rebuilt the carb did you get a new float with the kit? I dont have any answers here, just curious. Sure sounds like the float is hanging up somehow. Expecially since you dont see any dirt anywhere. Im sure you checked the vent in your fuel tank. That could cause it also.

Before you start the motor, what happens when you squeeze the primer bulb, does fuel just run out of the carb?

Almost sounds like there is pressure building up in your fuel tank from the way it starts pouring out when you connect the line to the carb.

[wallleye mike]

schrof;;; I have a '03 9.9 Big Foot and I also live in Northern Illinois. I have had NO such problems as you described. I tend to tow in motor down position, but ocassionally, leave it up. Good Luck..WM

[johnp034]

Jee whiz guys, don't you know when you buy one of those big black motors your not supposed to complain about them? Its a 2002 model, its over the hill, outlived its useful existance, out of warranty, those guys that are sponsored by Merc will hang you out to dry.

Seriously, this is only about the bazillianth post about the 9.9 Mercs flooding out. What has Merc done? Nothing, just keep making the same motor with the same problem. Just keep on rebuilding the carb or whatever you have to do and let Merc keep saying you abused your motor or you didn't break it in right or you used it to much or you used gas with too much alcohol in it, didn't winterize it correctly. Anything to make you think it was your fault. Again, thats if they even call you back to acknowledge your problem!

[schrof]

Perchjerker,

Yes, the kit does come with new float, needle valve etc.. I have checked fuel vent. And yes again, when I squeeze primer ball gas pours out even faster, thats how I immediately know there is a problem since I've experienced this several times. As someone else stated, I too am now trying to run all the gas out at the end of day, just frustrating that I have to do this. And I can see it already, tournament morning, running late and then this will occur, hope not nw.

[perchjerker]

Scrof-
I am going to send you an email about this.

Give me an hour or so.

[bobk]

I had the same problem. I always pull the fuel line off and let the gas run out of the motor. If I don't and trim the motor up to make a run the next time I try to start it it will poor fuel out. Shouldn't have to do this but it did solve the problem. It only seems to flood when I tilt the motor all the way up. I guess it's better than rebuilding the carb, but Merc really needs to fix the problem.
Bob

[BIG BILL]

My, Merc 15 has been doing that for the last 2 years. I just rap the float bowl and it quits leaking. The motor is in the down position all the time except when not in use on the water. Motor runs fine otherwise.

[Ex opti owner]

I still have my '99 Big foot and it too had the same problem. The carb was rebuilt 18 months ago and so far (knock on wood) the problem has not re-occured. I find it funny that you mentioned that there is bad gas in your state. We must get the same bad gas delivered here in Pennsylvania! LOL. That was the same reason Mercury gave me about my former Optimax motor running so poorly. That lame excuse did not hold up since I also purchase fuel in Ohio, New York and Ontario and the motor ran poorly in each of those states as well. Maybe they will blame it on solar flair ups next?