Fixed-jet v.s. adjustable carberator (small engines)

[steppinthrax]

I have a snow blower (old one) that has a bowl type carberator. There are two screws for adjustment. There is a main fuel mixture screw on the bottom of the bowl that adjust the amount of fuel going into the intake, there is also a low idle mixture screw.

I recently bought another tecumseh engine (2007). I noticed the carberator is exactly the same except that the screw on the bottom of the bowl is missing and replaced with a bolt and the low idle screw is capped and not meant for adjustment.

After further research I determined most small engine manufacturers are using non-adjustable carberators. What's the disadvantages of this?

 

[SpatiallyAware]

Disadvantage is that as the carb wears out over 1000's of hours things don't seat quite the same way and need adjusted. Same with rebuild kits.


Advantage is 99.98% of people who touch them should've left them alone.



BTW in my experience they typically use brass caps you can pry out...

 

[LTC8K6]

Emissions regs.

That's why your push mover only runs at one speed now.