Bad Surging 11 HP upright

[JoeVB]

Hello,
I am having an issue with an 11HP upright B&S engine on my generator.
It has always surged badly when running, I can add choke and it runs slightly better but still bad so I figured its a fuel issue.

I installed this new carb: https://www.amazon.com/dp/B099PQ7WYQ?ref_=cm_sw_r_cp_ud_dp_06FFVG3FCJ40V9R3NCY7
And this fuel pump rebuild kit: https://www.amazon.com/dp/B000A13FBU?ref_=cm_sw_r_cp_ud_dp_HTTBSA7BN27E06W70P3D

But still the same surging as before. Here is a video of the problem: https://www.dropbox.com/s/lt6ubhmewy6i0ck/IMG_1881.MOV?dl=0
Thanks for any help!
Joe-

 

[Scrubcadet10]

get some WD40 in a trigger spray bottle, with the engine running, saturate the area around where the carb bolts to the engine. If the engine, runs better or blows white smoke, or has any change in RPM, you've found your vacuum leak causing a lean running condition.

 

[JoeVB]

Thanks! I'll give it a try!

 

[slomo]

It has always surged badly when running, I can add choke and it runs slightly better but still bad so I figured its a fuel issue.

Fuel delivery issue, yes. Dirty carb, yes. Dirty fuel tank, probably.

Dirty cooling fins, most likely.

 

[JoeVB]

get some WD40 in a trigger spray bottle, with the engine running, saturate the area around where the carb bolts to the engine. If the engine, runs better or blows white smoke, or has any change in RPM, you've found your vacuum leak causing a lean running condition.

No change at all when spraying the WD40. I was hoping that would be it. I am thinking about rigging up a temporary fuel source that will feed that carb via gravity to see if maybe the fuel pump is not pumping enough fuel.

 

[JoeVB]

Fuel delivery issue, yes. Dirty carb, yes. Dirty fuel tank, probably.

Dirty cooling fins, most likely.

I haven't, I never thought about that, I will check.
The carb is brand new and the fuel pump was just rebuilt.

 

[slomo]

I am thinking about rigging up a temporary fuel source that will feed that carb via gravity to see if maybe the fuel pump is not pumping enough fuel.

Now you are thinking.

New carb means nothing. Especially if it came from Amazon or Ebay. New carb needs to be tested.

 

[slomo]

I installed this new carb: https://www.amazon.com/dp/B099PQ7WYQ?ref_=cm_s

Chinese carb alert!!

You need to ask Bertsmobile1 about his genius carb boiling method. I think this is the best way to clean these small carbs. I tried it once. Got kicked out of the kitchen by this barely 5 foot tall woman.

 

[JoeVB]

Now you are thinking.

New carb means nothing. Especially if it came from Amazon or Ebay. New carb needs to be tested.

Good to know, thanks. It sure was inexpensive, should have been a clue.

 

[JoeVB]

Chinese carb alert!!

You need to ask Bertsmobile1 about his genius carb boiling method. I think this is the best way to clean these small carbs. I tried it once. Got kicked out of the kitchen by this barely 5 foot tall woman.

Will do, thanks! Hopefully you've been re-admitted into your kitchen!