Briggs gas tank advise

I'm working on an older 5hp horizontal shaft Briggs engine that's been sitting for years. It has the large metal tank with a long carb on top. The tank looked very clean inside with no rust but when the carb was removed the little bowl/container/thingie that is under the carb inside the tank--you know what I'm referring to--well it's rusted away with big holes in the bottom and sides. I'm not sure the purpose of this bowl and I'm hoping someone here can tell me what it's for and if per chance the carb will work with it missing or how I can fix it. Those tanks are expensive! Cheapest I've found is $78 and there is no way this is worth spending that much on.

check with Brigges site or small engine repair shop- the carb pickup cup and tube are known expendable wearpoints, possible fail points and repair kits with tube, cup, gasket are available for $6.00 to $19.95 - price from couple years ago. Need to get part numbers, check Jacks Small engines site for parts - might get back up in 3 days. RN

The Briggs carburetor has no float so to control how much fuel is available the pump pushes an excess of fuel to this cup and the excess beyond what the engine needs simply runs back into the tank. Yes the Briggs really needs this cup.

To answer your question as to how it works -- it is actually quite complicated . Gas is sucked up a straw with a fine screen on the end - through a gas pump that uses crankcase pulsations to do the work -- then it flows into the little cup you mentioned -- excess is spilled out of a hole in the upper part of the little cup . This is how they regulate the gas level in the cup -- like I said excess spills back into the tank . Another straw with a fine screen is positioned in this little cup and the venturie (vacuum) action draws gas up past the needle adjusting screw and finally into the air flow. Problems with this set up include the two screens becoming corroded and plugged . The gas pump consists of a diaphragm made from a rubberized type of material that goes so hard over time exposed to the e 10 gas that it simply cant flex any more and of course slowly gets harder and harder to keep running. This set up also makes these engine very difficult to start when the little cup loses its charge of gas through evaporation or tiny rust holes in the bottom . You have to crank the engine many times to pump the cup full again. Easiest way to get around this is to prime the engine with a little gas by removing the air filter or spark plug . Some body did sell a primer bulb that was built in to the gas cap. It would pressurize the gas tank some what and force gas up into the little cup making the engine easier to start .

As said, that is the carb bowl, and it is necessary for proper operation.

Nothing to loose by trying to repair it.

I would scrape away the rust best you can, then rebuild the bowl with JB Weld. It won't be easy having to work through the small holes, but I think it can be done. Possibly make a small patch or cup out of an aluminum can, epoxy it in.

All it needs is a small bowl to catch enough fuel to keep the short pick up tube end submerged.

Is this going to be a working engine? If so, it will need the bowl repaired. But, if it's for show, the engine will run with a full tank until the short tube will no longer reach the fuel level.

I know a few old men who work on mowers and have a yard full of junk parts. That's where I would look for cheap old parts.

Thanks 9001Ron for the "how it works". Makes sense.

I actually thought I had another tank like that on a dead generator here but there are subtle but important differences in that tank.

But it occurred to me that the cup is structurally solid enough to hold a small "cup" in it. So I'm mulling over things I can use to make a cup to put in the cup. Copper pipe with end cap, pill bottle, metal cap off some container, thin sheet of brass or aluminum beat into a cup, aluminum foil, still thinking. Gotta make sure how much depth I have to work with too.

Also as suggested here JB Weld or by my neighbor Bondo body filler, some kind of epoxy, hot glue, still thinking. Humm does that stuff hold up to constant contact with gas?

I think I'm going to see how easily I can form a cup from that cheap brass planter on my scrap pile--if I can find it. I also wonder how well aluminum foil would hold up over time.

That is the place the fuel is sucked into the engine. It is needed because the level of fuel does not change as the fuel is used so the carb adjustments do not change as the fuel level changes. As others have said, JB patch or replace with garage sale parts. A little leakage would not be a problem. I agree that a chock full tank make the little tank full too eliminating the issue until some fuel is used. These were very common in their day, and I don't think you will have to look too far to find another one cheap.

Make it a hot rod motor. Eliminate the short pickup tube and put you a thin piece of aluminum under the carburetor so the fuel is pumped directly into the fuel office.

Dont use a pill bottle -- they dissolve in E10 gas

The more I read about the predator engine from harbor freight for the price I would not even mess with it.

(quoted from post at 23:08:31 05/01/19) I'm working on an older 5hp horizontal shaft Briggs engine that's been sitting for years. It has the large metal tank with a long carb on top. The tank looked very clean inside with no rust but when the carb was removed the little bowl/container/thingie that is under the carb inside the tank--you know what I'm referring to--well it's rusted away with big holes in the bottom and sides. I'm not sure the purpose of this bowl and I'm hoping someone here can tell me what it's for and if per chance the carb will work with it missing or how I can fix it. Those tanks are expensive! Cheapest I've found is $78 and there is no way this is worth spending that much on.

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That engine is used in the junior dragster world. The carb and tank are replaced with aftermarket parts. You could check with a junior dragster builder in your area to see if they have any takeoffs laying around.