Carb Troubleshooting

[mcheck]

Alright guys, here is my noob thread of the month....

Dont know a whole lot about carbs, trying to troubleshoot my issue. truck runs titties at idle and up to 3700 rpm. 3700-4k it seems to richen and flood itself causing the carb to kinda be a rev limiter if you will.

Secondary jets too big?

thanks for any and all help

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[manicmechanic]

Sounds like its going lean to me. Any smoke?.

[richard cretsinger]

blown power valve?

[CraigMT]

A little more info?

What Carb?
What engine?
Mods?
Fuel system type? (Mech or elec)
Regulator?
Fuel line size?

I had a neighbhor complaining of the same issue on a nasty little stroker motor. He felt the carb was flooding the motor after 4500 rpms. I found the fuel line size fed from 3/8 at the cell down to a tiny 5/16 at the carb. In reality he was running the carb out of fuel causing the motor to flatten out or 'bog' after 4500...

We changed the whole system to 1/2 inch lines and no more problems...

Don't know if this applies...

[tcrperformance]

Why don't you start your diagnosis with a A/F meter?

[pkonopasky]

Alright guys, here is my noob thread of the month....

Dont know a whole lot about carbs, trying to troubleshoot my issue. truck runs titties at idle and up to 3700 rpm. 3700-4k it seems to richen and flood itself causing the carb to kinda be a rev limiter if you will.

Secondary jets too big?

thanks for any and all help

Sounds similar to the problems I was having with a couple holley truck avengers... What carb is it? If you kind of baby it will it allow you to open it up?

[curtrnev]

Can you drive it ? make a pull put in neutral cut off engine and take a plug reading or can you have someone spray some carb cleaner while it is laying down to see if it is rich or lean. It sounds lean to me from the pops I heard on the video.

[bajaruner11]

It's sounds like it's going dead lean as soon as the secondaries start to open, what makes you feel it's rich. is it blowing black smoke?
Have you checked the float levels?
What is the fuel pressure set at?
Is the fuel pressure holding or dropping when it begins to bog? It should hold.
What Holley carb model are you working with there?

[CraigMT]

Just got the video to work at home... IT nazi's have the vid streaming locked down at work...

Definitely sounds like you are running way lean at WOT. Do you have a fuel pressure gauge inline to see if fuel pressure is dropping off?