I have problems with two stroke carburetors which I often end up solving by buying a whole new carburetor and replacing the old one. I think that somehow the orifices get clogged.

I have tried disassembling them and cleaning them in an ultrasonic cleaner, but it does not work.

Is there any way to test a small carburetor and make sure all the orifices are clear? The problem is that when I look at the carb it is basically a block of steel with a bunch of different holes in it, and it is not clear to me which hole connects to what so I have no way to tell if it has a blockage or not.


yours is a common problem, and there isn't any way to test the carb for blockages except by running the vehicle and noting any deficiencies in performance. the fix is to disassemble the carb and clean out the orifices with pieces of very thin wire. But there is a solution:

install a simple in-line paper element fuel filter upstream of the carb. these are small and cost only a couple of dollars at an auto parts supply store, and they completely solve the problem of dirt-clogged carbs.

  • $\begingroup$ The devices always have fuel filters. I think clogging comes from old gelled oil or bits of gaskets or gaskets come loose so vacuum is lost. My problem is how to figure out WHICH orifice or gasket is the problem. $\endgroup$ – Wallace Park Aug 6 '20 at 4:26
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    $\begingroup$ @WallacePark each orifice is associated with something, like idle or max throttle etc - once you know which function does not work then check the diagram and you will know which to clean... But I found it is best to clean the whole thing 100%. And that works for small carbs right up to twin 40dcoe webers etc $\endgroup$ – Solar Mike Aug 6 '20 at 6:02
  • $\begingroup$ agree with @SolarMike. also please note the fuel spoilage/jet clogging issues can be significantly reduced through the use of fuel preservatives like Sea Foam, and by running the carb completely dry before end-of-season shutdown so there's almost no fuel left in the carb to congeal during idle storage. $\endgroup$ – niels nielsen Aug 6 '20 at 6:22

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