Carb problems with B/S engines

[cyaw126]

I seem to have a lot of issues with motors surging even after cleaning the carb. I know there are other things that can cause this issue but my question is just carb related. Most of the engines I see have the Nikki carb which I have no luck with cleaning up and rebuilding so I have resorted to buying the cheap replacement ones off the internet. This I have learned is a total crap shoot weather you get a carb that will run or not. This leads me to my two part question , seems like a lot of the carbs are listed for multiple engines and it would seem to me that the jets would have to be different sizes for the different horse power engines is that a correct assumption on my part? and question two is do you guys order your carbs from a specific website or is it all just a crap shoot if you get a good functional carb. I just don't want to spend the money on the OEM version but I may have to .
Thanks for any comments

 

[Born2Mow]

If the motor runs, but surges, then you have cleaned the larger Main Jet, but most likely missed a tiny Idle/Accelerate Jet. And when I say "tiny" I mean the hole is maybe on the order of 0.005 to 0.008 inch for a small walk-behind mower engine. Too small to clean with a fine sewing needle. And all these carbs have at least 2-stage jetting, so it's there if you look.

Obviously, the smaller the jet, the easier the scuzz clogs it. You're going to need to look at the carb body again under a bright light with a magnifying glass. I keep a short piece of lamp electrical cord in my tool box. The very fine individual copper strands of lamp cord are perfect for poking through small jets. If you can ever get fuel to flow, then a carb cleaner, like StarTron, can do the finish cleaning.

Hope this helps.

 

[Rivets]

Most of the idle jet sizes I’ve worked on mower engines are between .015”-.017”.