Carb Repair Or Replace?

[mmadlener]

Good Day All!!<br />I am wondering if I should repair or replace my Carb (Mercarb 2bbl) on my 1991 4.3L V6. <br /><br />Turns out, the "Pin and Seat" is the cause for my problem. When the boat initially fires after sitting for a day or so, she will come to idle and run great. If I allow the boat to sit for more than a minute, the barrels fill with fuel and she floods herself, thus making it very difficult to start again!<br /><br />Anyway, I do not want to leave my safety or that of my family to chance; so should I repair the carb or replace it entirely?<br /><br />Thanks a bunch everyone!<br /><br />MadSearay

 

[TwoBallScrewBall]

Re: Carb Repair Or Replace?

That's an easy fix on the rochester 2bbl carbs, I just rebuilt mine. The pin and seat are what regulate the fuel into the bowl according to float position. If it's a mercarb, I can't talk from experience, but it can't be all that much different.

 

[doman]

Re: Carb Repair Or Replace?

i'd say rebiuld it ...i do have the same crab on my 3.0 entire kit for this carb costs around 50 bux it comes with everything <br /><br />Dom

 

[outboardguy]

Re: Carb Repair Or Replace?

You can rebuild it fairly easily, but I think I would take the top cover off and take a good look before buying parts.Sometimes they develop so much corrosion inside the carb its easier just to replace it.

 

[ncwest39]

Re: Carb Repair Or Replace?

GO GRANDMA!!!!!

 

[hoot]

Re: Carb Repair Or Replace?

sounds like your float has gotten heavy or not adjusted correctly. my float had a hole in it and dumped gas into the manifold like a madman. mercarb is easy to rebuild. float has 2 adjustments, 1 is the float drop, and the 2nd is float level at shutoff. you need to get the problem fixed, not safe to be dumping raw fuel into the motor.

 

[mmadlener]

Re: Carb Repair Or Replace?

Thanks Guys!!<br />I am thinkin that I need to open this darn thing before I come to any conclusions. <br />I have heard from several people that something as small as a grain of sand can get in there and foul the needle and seat. <br />Now, how much to I need to remove before I can see the condition of the "Needle & Seat?"<br />Again, sorry for not being mechanically inclined!!

 

[hoot]

Re: Carb Repair Or Replace?

been a while since i did mine, but what i remember is this; remove fuel inlet line and spark arrester. disconnect throttle linkage and choke. pull carb off of manifold. you do not want to drop anything down into the motor!! remove screws (about 8 or 9). top of carb should lift up. work carefully as there is a gasket between the top and carb body. watch closely for any balls or springs that might fall out. turn top over. measure float drop and shut off distance from top plate for reference. remove float. needle may be attached to float. inspect needle. seat is screwed into top plate. buy a can of carb cleaner and spray metal parts and into holes. my float was brass and had a hole in it, some floats are a composite material and can soak up gas and become heavy. reassemble carb, install back on engine, crank, and look for leaks!. there is no reason to replace the carb. you could take the carb to a repair shop and have a mechanic do the work if you are not comfortable with the work.

 

[Northern Eclipse]

Re: Carb Repair Or Replace?

There was a Merc TSB back about 92 or 93 for the Mercarb 2bbl addressing the Needle and Seat, there is a revised part, My family had 2 boats at that time with Mercarb and both of them did flood as you describe, once we had the new design part replaced it was never a issue again.

 

[mmadlener]

Re: Carb Repair Or Replace?

Northern Eclipse, <br />How would one go about obtaining this TSB recall?

 

[Northern Eclipse]

Re: Carb Repair Or Replace?

My dad and I had these repairs done back around 92 or 93 I went to Mercury in person and beefed with the warrenty claim office they told me about the TSB (Mercury has a huge warehouse head office just outside of Toronto) anyway it really wasn't a recall they made open but they did pay since my dads boat was brand new 1988 that he bought in 1989 but still only had about 20 hrs on it . The TSB is only a updated repair and part revision for Merc shops, all I'm saying is if you get a new needle valve and seat it will be a bit different than the original, but will be the correct one if you fix your carb it will be fine, You could try your luck with Merc but you now have a 13 year old boat and they will state you need a carb rebuild anyway

 

[Cobra SX]

Re: Carb Repair Or Replace?

MadseaRAY , all thes people have given you good advise. Just remember ....<br /><br /><br />1) Never start a rebuild UNLESS you have ALL the parts/TOOLS nessary for the JOB.<br /><br />2) Always Release FUEL SYS PRESSURE before working on anything with the fuel sys.<br />(release gas cap)<br /><br />3) CARB's are very touchy , more like tempermental<br />Always use clean lint free colths-NO DIRTY/DUSTY<br />Use clean bench , READ up on it first!!!! <br /><br />4) NEVER, NEVER soak Rubber/plastic card componets in CARB cleaner. Hurts them bad