Briggs engine

[Terryl]

I can see why you went with the clone carb, the OEM carb is $233, too bad you junked the old one, as the jets can be interchanged.

[dogdayz]

There's probably a mixture adjustment under the hex nut.Turn it counter clockwise to richen the mixture

Well Noof, I took off that hex nut and all it did was drain the fuel out of the carb.......

I don't see any adjustments on the carb except for the idle screw.

[The Noof]

Well Noof, I took off that hex nut and all it did was drain the fuel out of the carb.......

I don't see any adjustments on the carb except for the idle screw.

Then it's fixed jet.Normally the jetting is close enough to work out of the box.Make sure that the engine doesn't have "false air" from an a vacuum like at the intake manifold to cylinder head junction or something like that.It is also entirely possible that your Chinese carb solution is defective, as usual.

[dogdayz]

I just noticed a jet under that nut that is removable with an allen key but there is no adjustments.

It's just weird that I put this carb on to replace the original but they both cause the same problem ie choke has to be closed.

I have new gaskets on and firmly tightened.

[Terryl]

Well the fact that the choke needs to be closed to even run could mean that the idle jet needs to be adjusted or the main jet is too small, the old carb's main jet was possible gummed up.

Closing the choke restricts the air flow, giving the engine a richer mix of fuel to air so it has a better chance of starting.

What is the model number of your engine, I want to look at a diagram of the carb, or can you post some photos of the carb?

[dogdayz]

I posted above in #13 the carb that I bought from amazon.

[Terryl]

I was looking for the parts breakdown, I found this on Eparts.

https://www.ereplacementparts.com/briggs-and-stratton-422447405901-engine-parts-c-16758_17347_22087_202378.html

(view carb #4)

I would order a new main jet (#117) and a pilot jet if you want(#147) and replace the ones in the clone carb, (I would do the main jet first) the diagram shows where they are located.

All this because I think the main jet in that clone carb is too small for that motor, it's not supplying enough fuel to run the engine right when the choke is off.

[dogdayz]

I don't mind changing the jets but considering I had the same problem with the original carb I can't help but think there is another problem I'm missing.
I checked the crankcase breather and it looks ok. I'm just wondering if there may be an air leak where the intake manifold attaches to the cylinders like Noof was saying. I have never had the manifold off but the bolts are tight. I don't know if the gaskets may have deteriorated over the years. Unfortunately it's a big job to get at the manifold. I should have done this work when the weather was warmer. LOL

[Terryl]

One test to see if you have a possible air leak is to get the engine running (with the choke on) and using some carb cleaner spray around the manifold in question, if the engine changes speed then you know you have an air leak somewhere on that manifold.

Be careful around the exhaust manifold and muffler as the carb cleaner is flammable..

I sometime use WD-40.

[Terryl]

Well after looking at the carb diagram it looks like the pilot jet (#147 on the diagram) is inside the main body of the carb, this means you would have to disassemble the carb to get to it.

But the main jet (#117) is accessible by removing the hex bolt capping it off, I would try that one first, hopefully the new jet is the correct size.

[dogdayz]

If I get time I'll try the spray around the manifold tomorrow and see what happens.