Fuel in Oil

[slomo]

How long should I leave it sitting to check for a leak? So far I’ve sat my carbs few hours each and saw no leak. I then sat one over night with a 1 psi drop over 10 hours.

Re-read what Bert said.

Here below

it should hold 3 psi for hours

 

[rancher_mac]

Re-read what Bert said.

Here below

I was wondering more if it is normal to see a little drop over that long, or if it is indefinite amount of time it holds psi. When trying to research I see most people only test for about 10 minutes. I’ve worked a lot on my vehicles, but I’m new to working on small engines. Sorry for all the questions but just trying to figure out how to diagnose.

 

[Forest#2]

Yes, what you are seeing is normal.
Time to install and make a test run.
Sometimes a small prayer service helps on them Briggs just before doing the first test run after a operational procedure.

let us know how it acts.

When you start the engine let it idle and look into the carb throat. You should not see raw fuel being dumped. If you are seeing a mist of raw fuel when idling the carb is running too rich and the engine will not be smooth.
After its run and warmed up, if the carb has a adjustable idle jet do the smooth adjust with the engine idling slow then kill the engine and go back in about 5 min's and see if you see any raw gas in the intake below the carb.

On them old twin carbs that are really flooding severely gas will come out the top of the carb vent hole and can be seen with the air filter removed. The bowl vent hole is beside one of the air filter hold down screws.
When they are flooding this much the needle/seat usually is loaded with lots of trash or the fuel is bad and has a sticky substance that causes the float to stick. (the sticky stuff will actually get through the fuel filter at first but will eventually clog the filter also. The gas tank will smell like molasses when almost empty of gas. The molasses gunk is settled in the bottom of the fuel tank and the tank has to be removed for a good cleaning/flushing.

 

[rancher_mac]

Yes, what you are seeing is normal.
Time to install and make a test run.
Sometimes a small prayer service helps on them Briggs just before doing the first test run after a operational procedure.

let us know how it acts.

When you start the engine let it idle and look into the carb throat. You should not see raw fuel being dumped. If you are seeing a mist of raw fuel when idling the carb is running too rich and the engine will not be smooth.
After its run and warmed up, if the carb has a adjustable idle jet do the smooth adjust with the engine idling slow then kill the engine and go back in about 5 min's and see if you see any raw gas in the intake below the carb.

On them old twin carbs that are really flooding severely gas will come out the top of the carb vent hole and can be seen with the air filter removed. The bowl vent hole is beside one of the air filter hold down screws.
When they are flooding this much the needle/seat usually is loaded with lots of trash or the fuel is bad and has a sticky substance that causes the float to stick. (the sticky stuff will actually get through the fuel filter at first but will eventually clog the filter also. The gas tank will smell like molasses when almost empty of gas. The molasses gunk is settled in the bottom of the fuel tank and the tank has to be removed for a good cleaning/flushing.

Thank you again. I’ll update in about a week when I’m able to get to everything. Good info on diagnosing. The tank is almost completely empty so I’ll probably just run the rest of the fuel into a tank I have for bad gas. Maybe the last batch I got from the gas station was old fuel or something. I’ll go get some new non-ethanol gas and follow your procedure.

 

[bertsmobile1]

So there is nothing wrong with your needle & seat mechanically
Thus carb can be installed
However this does not mean a bit of crud will not get stuck under the needle a bit later on and prevent it from sealing then
This is why you have a filter on the fuel line

 

[rancher_mac]

Quick update. Almost to the point I can run the engine. I got a new muffler with a slight variance in the inlet spacing so I had to cut it. Having my neighbor take it to his work and weld it up for me. After a redneck valve job it has cold compression of 110 and 100. Clearances are all to spec now. I did check out the tank and what would you know…somehow what looks like a piece of a leaf got in the tank…that or it is aome kind of plaque that fell off from somewhere. Old filter was cheap so probably wasn’t catching it all. Going to hopefully do the first test run on Monday or Tuesday.

 

[bertsmobile1]

Debris gets into the fuel tank
If it is fresh vegetable matter the petrol will displace the water then the debris becomes almost invisible in the tank
It also floats because the mass is almost the same as the fuel
As you mow the debris get sucked into the outlet blocking it then when the flow stops, it floats away do do a repeat performance .

 

[rancher_mac]

I was just able to run it. It started up and runs well at medium idle. Turn it up and it surges real hard. I don’t see liquid gas when looking down the carb, both while running and when off. I do see gas settled in the manifold below the carb though. Is the 40 micron filter I replaced my old filter with too constructive? Should there be gas settled below the carb at all?

 

[bertsmobile1]

The faster it goes the more fuel per minute it needs
The way to diagnose your problem is to tackle one possibility at a time, eliminate it then look at the next

 

[rancher_mac]

The faster it goes the more fuel per minute it needs
The way to diagnose your problem is to tackle one possibility at a time, eliminate it then look at the next

Yep, going to be looking into a few things. One thing I noticed is the linkage seems pretty loose with the governor. When at low idle it won’t rest against the idle screw. Going to try to figure that out. Maybe the gov screw loosened up on me somehow or something like that. If not that I’ll go back to musical carbs and see if they all act the same way or not.