Carb. Jets? (1 Viewer)

[FIreguy13]

I am having carb issues! I know that it is a new problem on this site but I cant find any older post that give me an answer to my questions, so here goes! I have a desomged 2F that has been rebuilt 30 over with a header, missing cat and a 2 1/2 in exhaust and high flow muffler. the carb has been rebuilt and is working fine as far as I can tell but the performance is flat and it is running too lean. I am using the choke to compensate for it. I was hoping some would know if I can get bigger jets for the carb. of it there is some other solution I have not thought short of sending it out or buying a bigger (after market) carb. Thanks in advance!

 

[Pin_Head]

It is not obvious that the stock carb would need bigger jets, so there may be some other problem for it running lean, like a manifold leak. You can get larger and smaller jets from SOR.

 

[FIreguy13]

I guess I should have included this but I believe that the intake manifold is tight. It has all new gaskets and I have checked it with spraying carb cleaner around the edges to see if I get a idle response and nothing. So I ran out of ideas.

 

[60wag]

Are you sure the secondary diaphram is functioning? I played with alternate jets and had worse perfomance and poor emissions until I went back to stock jets.

 

[FIreguy13]

Thanks that is a good idea but I have rebuilt the secondary and I am sure that it is functioning. I do not have any emissions controls on it and I lost the cat as well so it is just carb engine and tranny as simple as can be. Plus my plugs are showing me that I am running a little lean. Thanks for the ideas! Always a great help!

 

[2mbb]

if it's a stock carb with working choke opener and choke breaker, then once the engine is running and heated up, the choke plate is no longer open, even if the choke cable is pulled out. At this point the only thing that is still engaged is the primary throttle shaft is rotated to the fast idle stop. If having the choke pulled seems to solve your problem, then you should adjust your idle circuit using the lean drop method.

 

[VTCDN]

No cat , Got an AREA that you can weld in a BUNG ?

Weld in a O2 bung , add a cheap HO2s , give it power to heat it up for testing the exhaust .2 white wires = heat circuit.
DVM , volt meter , thats QUICK , low voltage = lean

Or just make a unit, that sticks up the tailpipe while grounded that the Ho2s wires from the unit are external of the exhausting flow.
The wires give the HO2s the sensing air.
Non-CAT engines run .6-1.0 is normal .

Just another way to check ..

VT

PS. Volt range 000.1 + lean 1.00Volt = rich .
.5 volt and bouncing back & forth .4-/+ is good running Cat Computer controlled fuel system.