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A litlle more Briggs troubleshooting


GWGAllisfan

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Ran My B-10 some Saturday. It ran for a while then stalled and wouldn't restart. It acts like it's flooded. In an earlier discussion I noted that the carburetor manifold connection leaks. This time I noticed that while I cranked it, gas sprayed out of that gasket. Would this be expected?, shouldn't this area be under vaccumn? I'm planning to get another gasket during the week and try double gaskets, or maybe if i can find gasket material, cutting a thicker gasket to use.
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RANDY are you saying that it's leaking between the intake and the carb? if so one gasket should be enough. JJ also check both of the surfaces on the intake and the carb to see if they are flat.
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Yes the leak is between the manifold and the carb. The carb is a new one. I do suspect the manifold flange may not be flat. I though I'd try double gaskets before I tried to find a machinist to mill it flat. I suspect the resulting vaccumn leak is causing the mixture to vary and making my carb tuning not work right. If I understand right, an updraft carb should be very much affected by this.
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IMO, you likely shouldn't need to have it machined. Try removing it from the engine, cleaning up both ends of the manifold well, then clamping it GENTLY in a vise, and use a flat file to smooth off any burrs or high spots. Then, use Permatex or something similar that's gas resistant, and "glue" a new gasket onto each end of the manifold. After the sealant sets a bit, enough to firmly hold the gasket during assembly, bolt everything back together. Make sure you clean/scrape the head before reinstalling it, without gouging the cast iron... Personally, I've experienced more manifold leaks at the other end, where it bolts one the head. Some of these old engines used the manifold bolts to hold on a small metal bracket, so you had to use a gasket on each side of that bracket -- which was so thin it would easily warp from the heat of the head...
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Not that you need my affirmation Kent, but you hit something squarely on the head. Those two gaskets on either side of that metal bracket are critical. After I rebuilt my Model 19, I put a new carb on it but only put one gasket. When I could coax the engine to start it would not accelerate at all. Someone pointed out to me that I was missing the outside gasket so I put it on and that took care of the problem. I could not believe that the one outside gasket made so much difference so I took it back off to see if it was just coincidence that it worked. Sure enough, the engine would hardly even start again. I put the gasket back on and it fired right up and accelerated smoothly. Even though there was no gap that I could detect even with the finest feeler guage, that gasket was sealing a very very small leak that made the difference between starting and not starting. wpr
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All the above is true, But the question I have is why you have enough fuel in that area to "Spray" it out ? I would fix the flooding trouble while you have the carb off. Also, A better way to fix the flange area is to take a piece of sand paper, Stick it to a piece of glass. ( contact cement or even grease will do this ) and move the flange over the sand paper holding it as flat as you can. Lift the flange and look now and then. When the whole face is the clean metal, you should be good to go.
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I like the idea of using a piece of glass as a substrate for sanding, but I would use fairly fine sandpaper, better than 180 grit, I would think, for the rough sanding. Then finish sand it with an even finer piece. I've "polished" carb surfaces with a well sanded piece of Arkansas pine and rubber cemented crocus cloth. Glass would be flatter. But my question is this: What material would you make a gasket from? That is, the part that touches the engine block. Assuming you had to make it and couldn't buy it. Paper or cork gasket material wouldn't withstand the temperatures.
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