Mercarb questions

JHornsby3

JHornsby3

Well-Known Member
Nov 10, 2020
1,392
Sheridan Oregon
Boat Info
"Steele'y Tutz"
1992 300 Sundancer
Engines
Twin 4.3L W/Alpha One Gen II
Would it be best to replace the old 92 carb or rebuild? The PO used the carb as a step and broke the airhorn off the top. Then put a bolt to hold the cover and flame arrestor together so it would look "together". I can't seem to find any parts other than the rebuild kit. I also can't seem to find an old used one to take the top off of to rebuild mine.

I just despise not rebuilding something that can be rebuilt.:confused:

John
 
my go to https://www.carburetor-parts.com/ "Mikes"

But for the body tougher, do you have the full model # for the carb?

my "Previous Owners" idea of a rebuild.
When the top wont go on just push harder...
That's not a linkage that's a variable main jet tapered metering rod.

upload_2021-4-19_20-8-38.jpeg
 
I don't think your going to find any housing parts, just rebuild parts. You might could find a used (not rebuilt) one somewhere like Ebay that you could buy and rebuilt yourself or use as a donor. If it were me, at this point (like you I hate replacing something that just needs a kit of some sort - I rebuilt my Mercarb a few years ago using a kit from Mike's Carburetors) but with a broken housing, you might just be better off buying a rebuilt one at this point. They tend to run @ $300 or so rebuilt and ready to go.
 
There is no tag on it and I'm not seeing any numbers on the carb it's self. But from looking closely at it, it looks like it's never been taken apart. And like everything else I have had to replace, he was not a big fan of taking care of things to well. Mostly it's been a lot of cleaning and making things work like they should. Most things have been replacing commonly replaced items to make sure it runs properly.
20210414_173321.jpg
 
throat is okay? just retaining bolt support is gone?
Gotta say I would try to repair, (but I'm admittedly cheap)
Some small Square Aluminum tubing, Or possibly even some solid bar stock.

Carborator repair.png
 
USCG would love to see that. They take their job pretty seriously out here on the Pacific. Really a Rochester 2jet carb can be had for about $120. But those aren't "Marine" carbs and will get your boat parked for you. A repair like that would too. It needs to be rebuilt too. Last time I was able to get it to start, it was sputtering and backfiring bad. Then the starter decided it was going to act up. So I havent been able to get it turned over since we bought it.
 
BillK2632 said:
So what is "marine" about a carburetor in a boat other than the flame arrestor?
Click to expand...

I have asked that question many of times. And all I get told is it is marked "MARINE" on it for a marine application. Hell I can't find a part or model number, let alone anything stating marine use only.
 
I was curious as to what makes a carburetor a "marine" carburetor. I didn't go so far to try to find any USCG regulation, but here is what I did find. It has to do with preventing fuel from a flooded engine from dipping out or overflowing from the carburetor onto a hot engine in the enclosed engine room -- makes sense.

https://www.cpperformance.com/t-carburetor_selection.aspx
 
I also have noticed that the carb is "painted" with a very thick paint and looks to be sealed. I also see the "drain" hose but is installed at the top, back of the carb, just below the flame arrestor flange.
 
JHornsby3 said:
USCG would love to see that. They take their job pretty seriously out here on the Pacific. Really a Rochester 2jet carb can be had for about $120. But those aren't "Marine" carbs and will get your boat parked for you. A repair like that would too. It needs to be rebuilt too. Last time I was able to get it to start, it was sputtering and backfiring bad. Then the starter decided it was going to act up. So I havent been able to get it turned over since we bought it.
Click to expand...

I was USCG boarding officer and as long as the flame arrestor is in place and secured that’s all the law requires.

A marine carburetor is designed so that if the bowl over flows it must dump into the intake. Never externally. Essentially this would flood stall the engine before any fuel could leak into the engine spaces.

In addition it has a port to dump any leakage from the fuel pump the same way into the intake.
 
I find it funny(not ha ha) that the non marine carbs are so cheap. But the marine ones are anywhere from $250ish to $900. That is a huge swing in pricing. Must be due to the Rona.o_O
 
So to follow up on what is going on with this.

The V6 carb is a magical unicorn. There is a bunch out there for the 4 bangers. I did find one new old stock Mercruiser one for $1200. I passed on it as this is just wrong to price something that crazy. And I get the whole supply and demand thing, but that is just plain crazy.

So as a last resort, I called up the localish repair shop. He had two old ones in a box that were not really complete. That was all he would say. So I asked him if he would just go ahead and take mine and one of his and make me a good one. He agreed on that for $350. Now that was very fair. So in two weeks or so, I will have a good working Mercarb for a 4.3l V6.

Now to find a thin guy to reach that port starter in the next two weeks and I should be golden.

John
 
To end this thread with the final results.

The shop had to use two of his carbs and mine to make one good one. So I ended up paying $500 for the one rebuilt using three. Seems the Mercarb came in two sized bores. One for some 4 cylinder motors and one for the larger 4's all 6's and some V8's.

Got it home, threw it on and hooked up and she runs like a champ. Just needs a little fine tuning and all will be good. Now I might need to rebuild that Starboard carb, just for good measure.
 
Scott06 said:
Glad you git it straightened out if this happens again … I think this kit may have saved your oriigninal airhorn https://quadrajetparts.com/rochester-cleaner-repair-bracket-large-bore-p-500.html
Click to expand...

If you would have sent this three weeks ago, it would have saved me about $250. LOL They told me $100 for the carb on the shelf but when I picked it up he charged me $250. When I questioned him, he said there is a spot on his shelf for my carb. I took that as pay up or get out. It was great to hear that motor fire up and run smooth like it should. Think I might need to rebuild the other one now.

Thanks Brother
 
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