CMB 90 Goldhead carburetor needed

Intlwaters

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BigChuck

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Old school gold head carb and plate are one piece unless it has been modified.
 

Wasted wages

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Lots of people just clip the needle off and put the cap back on and use a third channel needle valve or fuel doctor. No low speed needle.

You can also drill out the spray bar if you don't go too crazy, others with machining capabilities have made replacement bars.
There are even a few older carbs that use a venturi ring with no spray bars at all.
C/B carbs if I remember correctly..
I personally like those carbs, they worked nicely...

I have personally clipped my needles, and cut the tip of the spray bar at a 45 degree angle, and used a fuel doctor.. worked fine.
 
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Wasted wages,

Thanks for the info, it’s greatly appreciated. That’s what I am going to do. I want to run a third channel on this set up. What’s a good one for that motor? Or doesn’t matter?
 

Wasted wages

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I like the fuel doctor type... small aluminum block with a brass barrel... others like the typical needle and mounting base style.

You can also find an original CMB remote needle that screws right into the carb and replaces the spraybar ( I think that's how it works )
You then have the throttle on one side of the carb and the remote needle on the other side.

If you are looking to mount a needle valve block to the stringer inside the boat,, check with Don Ferrette here on I/W,, he makes and sells the mounting bases, and probably can point you in the right direction for the needle assembly.
This is Don's setup..
216541-b9d56b80c609260b37840ab037aee202.jpeg

BTW, does your gold head have the body of the carb molded into the back plate? Or does the carb body bolt on ? Or does the carb slip into a hole and have a setscrew to hold it in place?
CMB made several different designs.
 
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May 27, 2022
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This is my first boat build. I owned an 8th scale hydro boat years ago. But that was an RTR boat.

I’m going to dig into the motor, later today. I have been focusing on the tub and sponson. I got a good deal on a we slightly dinged up rigger. The reason I bring this up is, that block you sent the picture of. It has something almost identical to that. I thought it was possibly a manual shut off for the fuel. But now I see I was mistaken. Lol I will get back to you on how it mounts on the motor. I greatly, greatly appreciate your help.

Thanks
Will
 

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Wasted wages

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Exactly!!! That's all you need....just make sure it's clean, and that the o-rings are good and not leaking...give them a bubble test in a glass of water.

BTW, if you look into the valve, you will see one side has a large slot, and the other a thin slot. The large slot goes to the fuel tank, the thin one to the carb.
 
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Nice to know, I was curious about which one went were. It moves freely with no issues.

My carburetor on my 90 is part of the plate assembly. Only issue I have is it was missing a idle adjustment screw. I believe that is what it is for. Not totally sure. It’s on the top of it. The second pic shows the hole. That is why I was looking for a replacement carb in the first place.

Thanks
Will
 

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Wasted wages

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I believe the screw is double duty, holds the barrel in place and acts as a low idle..
Which on a boat should be fully closed.
Set the idle with the radio trim...and fully closed to kill the motor as it comes to shore..

Is the hole in the carb body in good shape?
Threads ok ?
I may have a stock screw and nut I can send you..
 
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Yea the threads are in good shape. Your right cause there’s a grove cut into the barrel that it fallows. You would be a life saver. I have been putting off on my boat cause of that. Been looking for 3 months. Name your price.

Thanks
Will
 
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