Mod. Yamato Question?

[johnml390]

We need help with turning our Mod. Yamato 80 carb into a floatless carb. Any help, suggestions... a number to someone that can help with parts/etc. Any information really. Thanks guys.

[Jack Stotts]

John, an alternative is to make a very, very small fuel tank that holds about 3ounces and mount it on top of the motor on one of the mounts where the original tank was mounted, feed your line from the fuel pump to it and have it feed the carb by gravity as in the original configuration. You'll need an overflow line back to the main fuel tank to get rid of the excess fuel that flows to the minitank . This is done by a lot of folks and keeps the fuel system simple and you don't have to mess with your carb.

Planning on making it to the Winter Nationals and will have Dan Parker in tow.

[johnml390]

John, an alternative is to make a very, very small fuel tank that holds about 3ounces and mount it on top of the motor on one of the mounts where the original tank was mounted, feed your line from the fuel pump to it and have it feed the carb by gravity as in the original configuration. You'll need an overflow line back to the main fuel tank to get rid of the excess fuel that flows to the minitank . This is done by a lot of folks and keeps the fuel system simple and you don't have to mess with your carb. Jack

Thanks for the response Mr. Jack, that is something to think about giving a go. We are currently running our Mod 80 with the normal setup... (Yamato tank up top just like the stocker.) We are wanting to experiment with a few other ways of running it. We would like to make a floatless carb to do away with the up top tank and lower the center of gravity a bit.

Jack- I sure missed seeing you at the few races we attended last year. Hopefully THIS year we will make more. I hope I have the luxury of entering the first turn beside you at least at one two of the race we make this year. You going to be making over for Winter Nats??

[Jack Stotts]

Getting rid of the large tank is a help but the system I proposed will do that without having to change the configuration of the carb which, in some instances, becomes a problem getting the float level where you want it. I've seen minitanks make of wood with epoxy seams or small alum. cylinders. It does not need to be very large. Good luck-have fun. Tell Dad that I said hello. Jack

[Team B&H]

You don't even really need a top tank with any volume at all. A simple T fitting mounted about the same height as the tank, even with the bottom of the old tank will do. Put a T connector in the line from fuel pump to carb and a line from that T to the top fitting. The top fitting has a return to your main tank and a very low pressure check valve to let air in but no fuel out.

[Team B&H]

Here's a pic of a fuel pump on a 302. An 80 is very similar.

[johnml390]

Here's a pic of a fuel pump on a 302. An 80 is very similar.

This setup, thats pictured. Is the carb floatless, or is the float still in the carb. Would you by chance have a pic of how the lines run to the carb itself?
Where would you find a check valve like that? Thanks for the response.

[mercguy]

This setup, thats pictured. Is the carb floatless, or is the float still in the carb. Would you by chance have a pic of how the lines run to the carb itself?
Where would you find a check valve like that? Thanks for the response.

BTM also makes a kit that uses a Mikuni style fuel pump, but the OMC pump can be used also. You still retain the stock float setup.

http://www.btmco.com/New_Items.html

[Team B&H]

The fuel line to the carb can be seen in this pic easily. The carb remains absolutely stock with the float.

[reed28n]

20h

Do you think this same system would have worked with the Carter Carb on the 20H, i can remeber my dad fussing with a pressure regulator and siliconing the dial to one position....

This would have been a little easier way to get to 1G....

[Larry Mac]

The fuel line to the carb can be seen in this pic easily. The carb remains absolutely stock with the float.

I was just curious what is the purpose of the check valve. When the pump is pumping the check is closed and the gas goes to the carb and by-passes back to the tank. It looks like the only time the check comes into play is when the motor is shut down. Why do you even need a check? What am I missing.
Larry Mac,

[Team B&H]

The check valve only serves to function when the engine has been shut off. If the engine is shut off and the return line has enough fuel in it and the carburetor inlet needle valve is open, the returning fuel can siphon the float bowl dry. You could always pump the carb full every time you want to start the motor, but the check valve makes it behave just like a stock set up so the float bowl stays full.