How to clean mercruiser 3.0L carburetor - beginnner asking

[halcrimm]

Good morning all, I am in the beginning stages of getting my first boat in running condition. Boat has been cleaned up and electrical is working. Now it is on to the engine which I have never dealt with before but am looking forward to learning how to do.

1992 Mercruiser 3.0L Alpha II with S/N OD714746.
I have been told to start with cleaning out all the old gas from the tank, lines and carburetor.
There are many good threads on here about carburetor repair but I am looking for guidance on how to disassemble, clean and reassemble, kind of a step by step with things to look out for. I ordered a repair manual but it will not arrive until next week. Looking for a weekend project. Again, this is the first time doing this, so I am sure that I will have questions throughout the process.

Are there any parts I should get prior to removing the carburetor, i.e. gaskets, springs, cleaning solutions? I am sure these are pretty basic questions but I have to start somewhere.

thanks all.
Hal

 

[abrx7]

Re: How to clean mercruiser 3.0L carburetor - beginnner asking

I don't have a step by step guide but I can offer a tip. I had that same exact motor. When you take all of the jets out, use a tiny drill bit and by hand clean out all of the ports. DO NOT USE A DRILL. I had my carburetor rebuilt by a mechanic and noticed I was still having a lot of problems on acceleration. I took it back apart and noticed that the secondary had some gunk in it. Also get a couple cans of carburetor cleaner (Not brake cleaner). Don't be afraid to be very generous with bathing it. When putting it back together, screw in the main jet all the way in. As soon as you feel it bottom out do not force it in more you will bend the tip. Then back it out a turn and a half. That will get you a baseline and back up and running. Any final adjustments will have to be made out on the water when you can put a load on the engine.

 

[oldjeep]

Re: How to clean mercruiser 3.0L carburetor - beginnner asking

What is the reason you are messing with the fuel system - does the boat not run properly?

 

[halcrimm]

Re: How to clean mercruiser 3.0L carburetor - beginnner asking

I was going to clean the fuel system because it has been sitting for 4-5 years and everyone that I have talked with has told me not to even try to start the engine until the fuel tank, fuel lines and carburetor had been cleaned.

 

[oldjeep]

Re: How to clean mercruiser 3.0L carburetor - beginnner asking

Guess I would have just siphoned the tank, added fresh fuel and started it up.

 

[fat fanny]

Re: How to clean mercruiser 3.0L carburetor - beginnner asking

1st off get the proper rebuild kit for the carb use the serial # stamped on the id tag of carb to make sure you get the proper kit. Go to the parts store and get a can of Barrymans carb dip($20.00) the instructions in the kit pretty much gives you a step by step to rebuild the carb. But 1st make sure you have a well organized work area pleanty of light and room it's also a good idea to have a couple of old baking sheets to put the parts on (some are small). 1).dissasemble the carb,2). wash all parts in warm soapy water, 3).blow all passages out with compressed air and clean orafices with a torch tip cleaner, 4). soak all parts in carb dip except plastic pcs, for at least 3 hrs, 5). blow all parts off and all passages out with compressed air again!, 6). wash all parts with soapy water again, 7). re-soak all parts in carb dip again!, 8).blow off all part and all passages out with compressed air, 9). reassemble carb per instructions I like coating the gaskets with vasoline incase a float re-adjustment is neccessary this will prevent them from tearing and sticking it also helps them seal. It is just like building a model car or plane take your time stay organized but remmeber a carb rebuild is a 50/50 shot of success but these instructions have never failed me yet. Also forget about the can carb cleaner it will not get to the small passages the soak is a better beat for success. Good lick and post back.

 

[ricohman]

Re: How to clean mercruiser 3.0L carburetor - beginnner asking

I've rebuilt 100's of carbs in my day and we all have to start somewhere but even as a beginer you need to understand exactly how a carb works and what every single part does before tearing it apart.
What symptoms does the engine have?

 

[oldjeep]

Re: How to clean mercruiser 3.0L carburetor - beginnner asking

I've rebuilt 100's of carbs in my day and we all have to start somewhere but even as a beginer you need to understand exactly how a carb works and what every single part does before tearing it apart.
What symptoms does the engine have?

Sounds like no symptoms - he bought a boat that had been sitting 4-5 years and someone convinced him it was a good idea to take apart the whole fuel system without seeing if it ran.

 

[halcrimm]

Re: How to clean mercruiser 3.0L carburetor - beginnner asking

Yep, Ricohman and oldjeep. That is exactly what happened. i have heard more times than none that I should not even try to start it until the carburetor is cleaned out. I would love to put some fresh fuel in and see if it works.
Unfortunately, being an engine beginner trying to learn I try to listen to what others have to say.

Will it or can it hurt to see if it will start in the condition that it is in? If the answer is no then that will be the weekend project.
I do understand that if it isn't broke, don't fix it. I guess sometimes I just don't know what I don't know.

So, with your best advice, should I try it or clean it?

 

[ricohman]

Re: How to clean mercruiser 3.0L carburetor - beginnner asking

It won't hurt a thing to try and start it unless it has a float bowl full of crap from rotten lines or the float is submerged. Make sure its got fresh fuel, oil and filters and fire it up.
A float bowl will only have minor crap from one full bowl evaporating.
I've ran many engines that have sat for far longer. If it runs good there is no reason to pull the carb apart. If the idle circuits are plugged or the mains then you have a reason to pull it apart. Never use drill bits in your jets. Drills are for brain surgery, not carbs.
I've repaired a multitude of carbs that some backyard mechanic wanted to "hog out".
Run it and see what you have, then go from there.

 

[halcrimm]

Re: How to clean mercruiser 3.0L carburetor - beginnner asking

New oil and filter tomorrow, Fresh fuel and an update tomorrow evening.
Let the fun begin.
And I guess if nothing else. The horn was returned to working order tonight. Darn bugs nest.