Re-building a 2BBL carb ( Merc140/Chrysler carb )

[jamesr1]

Any good references. This is my first rebuild, and would like to make sure I do it right. My manual stinks, it shows the break down of the carb but no step by step procedure. Also,, is carb leaner from a spray can, and good gas what I clean it with or is there a preffered solvent?

 

[Don S]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

To be honest, if you need step by step instructions to rebuild a carb, then you would be better off getting the job done by a pro. <br />No, the spray doesn't work for rebuilds, you need to soak the parts in carb cleaner (NOT Gas).<br />Your best bet for instructions is from a Mercruiser service manual for your engine.<br />You also MUST get all the settings correct or you are not rebuilding, just disassembling and replacing gaskets.

 

[jamesr1]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

Don,<br /> Perhaps your correct, but, there have been many things in life that I have never done, and yet, looking back I find the expeirenece was good. I have learned alot along the way. I dont know that I need step by step instruction. Seems to me the adjustments are the only thing that may be tricky, other than that, just getting the carb clean and replacing a few parts. How hard could it be?

 

[Mahoney]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

Jamesr1, Normally ths is not a tough proposition, and I would check for your specific model on the internet, when I did my rebuild, there were a multitude of sites that walked through ths process, step by step. There are also many books on the subject, as well as included in the service manual for your engine(which sounds to be insufficient from your post). One gotcha, which is I think what Don was hinting about, is that during the process of taking the carb apart and reassembling, a profesional will be able to spot things that could be wrong that a simple rebuild will not fix.<br /><br />I love taking things apart and learning more about what is going on with my engine, and I am pretty sure you will be able to succesfully complete the proceedure if you follow the steps in a manual, but without specific knowledge of what problems to look for, it is also possible, depending on the condition of the carb, you might miss something, and still be back where you started, although one carb rebuild will be under your belt.

 

[rabidfish]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

I agree with Don also...<br /><br />I also know the satisfaction of doing my own work. While I applaud the efforts of those who "DIY", I also know there are limits.<br /><br />I hate to say it, but most mechanics these days simply overhaul a carb, never even knowing what's wrong with it. Simply cleaning it and reassembling with the componants of a kit is not a proper repair. To make a real carb repair, you simply MUST understand how it works, and what goes wrong when it isn't. <br /><br />As for solvents... depend on why you're rebuilding it. Is it clogged with varnish? or is it corrosion from moisture(water)?<br /><br />In this case... If you can get the proper Mercruiser manual, and follow it, then fine. But if you cannot... Find a pro.<br /><br />One really good reason to find a pro: It shouldn't be a Chrysler carb... There would seem to be a major issue with knowing even what you're working on... (I am not berating anyone here, intentionally. But it seems to me a knowledgeable look is what might be needed)

 

[jamesr1]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

I have been purchasing parts from Napa, and thus far they seem to be able to get what I need. The Chrysler Id came from the tag and stamp from the carb itself. Tag reads: MCM 120/140 1389-8490 I found it odd myself setting on a GM motor, but after examining the rebuild kit with the old parts, they all seem to match perfectly. The boat sat with bad gas ( old and plenty of water ) for a season+. Prior to buying this boat I had never been past changing a head gasket. I have already accomplished tasks that I could have paid $1500-$2000 to have done. As far as the carberator, I would very much like to know what it is, if it is not a Chrysler?

 

[Don S]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

I have been purchasing parts from Napa

First of all, you may have a Mercarb, this is a Mercruiser carb and you won't be finding parts for it from NAPA. See your local Mercruiser dealer for parts, or many places online to get Mercruiser parts. <br />What is the year of your engine, better yet, what is the Serial number. Merc origially had Rochester carbs on many of the older 120's and 140's, but any replacements were replaced with their Mercarbs. They can be identified by the single fuel mixture screw instead of 2 like the rochester had. At fist glance, the carbs look the same.<br />One reason for my concern, is that when an automotive carb has something done wrong on it and it leaks, or overflows, the gas goes on the road. With a boat however, you end up with a bilge full of gas, AKA a bomb waiting for a spark, and if you happen to have automotive starter, alternator, or distributor or ????? that should be marine, you have the spark necessary to cause the big bang theory of boats.<br />And it sounds to me like you don't know the difference between automotive and marine or really why you are doing something or what to look for.

 

[jamesr1]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

Actually ,I do understand that there is a difference between marine and auto. I also understand that there is a GM motor with a stamp that says Mercruiser 140 on it. I also understand that Mercruiser purchased these motors from GM, and that Mercruiser very well could have gotten the carb from chrysler. ( not to say that this is the case ).

 

[Laddies]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

James by the number 1389-9490 your carb. is a Merc Carb built oveseas for Mercruiser. The kit for it is 18-7097. the kit should have instrutions and specifications if not I would ask the point of purchase man were the instructions went and yes you can buy that carb. kit at NAPA, CARQUIST,AUTO VALUE and many other parts places, just use the uppermost care in doing the job--Bob

 

[rabidfish]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

Ditto. <br /><br />Actually, Sierra make the kits for both NAPA and Mercruiser OEM replacement parts(1395-804844)(or possibly 1395-804845), so the NAPA kit is the same you'd buy at a dealer.<br /><br />Good luck, let us know how you make out...

 

[Buttanic]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

I have found lacquer thinner to be about the best solvent for cleaing carburators. Just don't soak any rubber or plastic parts in it.

 

[jamesr1]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

The rebuild was easy. The carb is on the motor and seems to be working great. I will know more after I get it in the water. Thank for the advice. I do greatly appreciate it, even when its not what I want to hear...

 

[jamesr1]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

OK, so if rebuilding a carb is so dangerous, how about explaining what to look for during and after the job is done, so that my boat dosn't blow up. Advice would be helpful and appreciated, but as some have suggested,,, if you dont want to help, then just move on...

 

[Laddies]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

James just make sure there are no leaks or sepage around the carb--Bob

 

[jamesr1]

Re: Re-building a 2BBL carb ( Merc140/Chrysler carb )

Thanks Bob, I have been watching for leaks everytime I run the motor in the driveway, as well as periodically on the lake. I have run about 15 gal of gas through the motor and all has been great thus far. I have accomplished many task with the help of others on this forum and the advice is appreciated. I will continue to inspect my motor for gas leaks, and or any other deficiencies.