4.3L Mercruser carb replace or rebuild?

tedhelms

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Sep 29, 2008
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I have a 4.3L that has been sitting for two years i put new batt drained fuel tank fresh gas and it crunk up and ran but not good the oil had water in it so I changed it 4 times and it was still getting water in the oil so i checked the compression 2 cylenders were 115psi so I then replaced head gasket, riser gasket , intake gasket , exaust gasket now i am to the carb there was a little rust on the butterflies do i need to replace or try to rebuild? and what carb do i have on the bottom i found this number 07265172 and on the top i found this number 8867 will these identify this carb?
 

Gary H NC

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Re: 4.3L Mercruser carb replace or rebuild?

The long number should be the carb number...Its probably a Mercarb.
Any Mercruiser dealer should be able to get a rebuild kit.
If not look at this site you can buy a reman or they will rebuild yours.
http://www.flyingfishcarburetors.com/Y38-3.htm

I have bought from them and they do good work.

If it runs ok i would leave it alone...:)
 

tedhelms

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Sep 29, 2008
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Re: 4.3L Mercruser carb replace or rebuild?

is there somepthing that i can soak it in to clean it before i put it back on ?
 

180shabah

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Re: 4.3L Mercruser carb replace or rebuild?

Have you confirmed that there is no more water getting in the oil???
 

Gary H NC

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Re: 4.3L Mercruser carb replace or rebuild?

Have you confirmed that there is no more water getting in the oil???

Really! That would be the most important thing before the carb.
Just soaking the carb will do very little without taking it apart and doing a rebuild.
 

tedhelms

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Sep 29, 2008
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Re: 4.3L Mercruser carb replace or rebuild?

i have not ran it since i put the head gaskets on. The manafolds and risers were in good shape with verry little rust there was no gasket between the manafold and riser just some type of sealer. is there anything else that could be a water problem i just wanted to put everything back ready to go . i have fixed tons of things that were not done rite by who ever worked on it before me is there anything else that i should check or do i checked the compression after the new head gaskets and had 177to181 on all cylenders specs say 180 thanks for the help
 

chiefalen

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May 18, 2008
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Re: 4.3L Mercruser carb replace or rebuild?

Does it get cold where you are?

Could have a internal crack in the water jacket if the motor froze up.
 

Chris1956

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Mar 25, 2004
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28,074
Re: 4.3L Mercruser carb replace or rebuild?

Ted, The gasket between the riser and the manifold is absolutely essential. I recommend you get one from MerCruiser, since they are the best. Also it will be best if you true up the riser surface before installing the gasket. I use a piece of plate glass with some fine emery cloth or crocus cloth taped to the glass, to true it up. True the manifold if possible as well.
 

tedhelms

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Re: 4.3L Mercruser carb replace or rebuild?

it does get below freezing here eastern north carolina but the water was drained from the block i did get riser gaskets and put them on the surface looked good they were not rusted or pited.
i have a new question i think that there is supposed to be an alarm for low oil getting to hot there is a sticker that sais that i should hear it for a sec when i turn the key on but i do not where do i start looking for the problem i do not want to put to much $$ in the boat it is for SALE but i do want to sale a good boat not rip someone off
 

Chris1956

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Re: 4.3L Mercruser carb replace or rebuild?

Ted, If you have the optional warning system, there are two oil pressure sensors and two water temp sensors. One of each is connected to the gauges (if you have them). The other sensors are connected to the horn under the dash.

The water temp senders are located on the thermostat housing on top of the block, in the front, where the raw water hose connects. The oil pressure senders are located in the back of the block. The one that is silver dollar shaped runs the warning system. The larger "juice glass" shaped one runs the gauge. the warning system uses tan and tan/blue wiring. Grounding any of the two sensor wires should trigger the alarm.
 

MERIT6419

Petty Officer 3rd Class
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Sep 3, 2008
Messages
89
Re: 4.3L Mercruser carb replace or rebuild?

That Is A Good Carb Very Reliable I Would Have It Rebuilt
 

chiefalen

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May 18, 2008
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Re: 4.3L Mercruser carb replace or rebuild?

I admire you for not wanting to rip someone off.

Someone raised you right.

The water in the oil is the main concern if it is running you have to see if you fixed that problem first.

You have no water in the cylinders?

You pulled the valve covers off see milky oil there?

You say it had 117 on 2 cyl. Hows compression now after you put new gaskets on?
 

tedhelms

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Sep 29, 2008
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Re: 4.3L Mercruser carb replace or rebuild?

sorry its been so long i got everything back together and compression was good on all cylinders i had a marine tech come out to my house and set timing and check carb everything seemed to be good until the starter loosened up and messed up the threads in the block i was able to fix that problem but i have read a little about a bracket at the front of the starter but i cant find anything out for sure . any ideas?
 

mthieme

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Oct 6, 2007
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3,270
Re: 4.3L Mercruser carb replace or rebuild?

The bracket is for the bigger starters. It is relatively small, maybe three inches with a slight bend. One end has a short bolt in the block, the other end attaches to the front of the starter.
I'm guessing you have the mini starter which I have seen loosen before. This is a direct replacement for the larger starters, requires a new bolt kit and the bracket gets pitched.
 
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