Hey,

Mower began surging ar low idle this year. Research is saying welch plug is common issue. In this pic, I notice an opening without a cover. Is this where a plug should be? Would you also be able to provide a part #?

Can't get the pic to upload. Looking down from the top just right of the air hose there are two openings on top of carb. The top right corner has a silver cap. The opening closest to the hose and left of the top right one is open. It also looks like there is a very small hole in the open one.

Thanks!

Can you post a pic using:  https://postimg.cc/files  .
 
It's free and easy to use.  Use the link for "forums"...
 
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Blow and clean with brake cleaner all that dirt in there.  
We need to see what's in there exactly.
 
It's hard to tell if there's an opening inside that orifice, which, in that case, would likely 
have a plug (and W/O it would cause a vacuum leak and erratic behavior.
 
I'd be curious if holding/ plugging it as is, makes any running difference..
 
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