# How to adjust an unadjustable carb.. My Way



## TNHermit (Jul 14, 2005)

Got the string trimmer out to get it ready. Run like crap needed carb adjusted. I don't believe all this other excuses. there is a reason for adjuster for the last 100 years. EPA can bite me

Its non adjustable or so they thought.

You need a short piece of 1/4 copper tubing
a 23 guage finish nail. THese are the kind they shoot from the new small pinners so you might have to ask around to your buds or buy some (about 7.00) or anything that is 23ga. It needs to be about 1 inch long

Mark ,scratch a line on the adjusters for reference
Take a short piece of 1/4 copper tubing and you should be able to push it down around the adjuster.
Mark and cut the piece of copper tubing about 3-/16-1/4 taller than the casting. This is not critical you just want to be able to get a hold of the tubing with a pair of pliers and see the marks on the adjuster screws..

Put the short piece of tubing you cut down over the screw. With a needle nose stick the 23 ga between the flat and the tubing. IT won't go down so you need a little hammer and lightly tap it done the side. its just a easy wedge and doesn't stress anything

Take a pair of pliers and turn the tubing the direction you want to go. The 23 ga will wedge itself and you'll see the screw turn.

Once I figured out it took me about two minutes to adjust them both 1/2 turn out. Thing runs like a champ

The inside of the 1/4 copper is around .193. And I have a old Phillips screwdriver with the just couple thousand bigger shaft. I will probably try and solder the 23 ga in the 1/4 tubing and then I can slip the screw driver in the tube and essentially make a tool or bit for the screw driver. But just the tubing and pin si the ******* way to do it. I got three more carbs todo. 

Most carbs on these things are Walbro or Zama so it should work on any of them

Could have had them all done time I wrote this


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## Bret4207 (May 31, 2008)

What are you referring to as "non adjustable"? Do you mean the limiter caps? They come off fairly easy. The knurled outside of the screws is not a big deal, there are screwdrivers available for a buck or so for them or for the "D" shaped ones. The on;y issue with the screws used with the limiter caps is that some have for friction stop, no springs or o rings to keep the screw in place. That's usually why the limiter has to go back on.


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## TNHermit (Jul 14, 2005)

Bret4207 said:


> What are you referring to as "non adjustable"? Do you mean the limiter caps? They come off fairly easy. The knurled outside of the screws is not a big deal, there are screwdrivers available for a buck or so for them or for the "D" shaped ones. The on;y issue with the screws used with the limiter caps is that some have for friction stop, no springs or o rings to keep the screw in place. That's usually why the limiter has to go back on.


The hi /lo adjustment screws are smooth on the outside and they don't come off. If you want to adjust them feel free to buy a special screw driver . They run between 40-60.00. I sure wouldnt have wasted the time figuring out for a 4.00 screwdriver ,and a trip to town 13.00


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## plowjockey (Aug 18, 2008)

If your carburetor was "in" adjustment last fall, why is it "out" now?

My string trimmer runs lousy every spring in the past few years, from sitting with even a tiny amount, of garbage entanol, in the fuel system. I have to carefully take it apart (to preserve the diaphragm and gaskets) carefully clean, every tiny port and then it runs fine for the rest of the summer.

EPA or not, I see no reason why any modern small engine carburetor, should even need adjustment, unless there was radical changes in fuel, altitude, etc.. In the "old days" casting and machining tolerances, were not very close, so adjustable jets, made up for the difference, which of course ,could eventually work their way "out" of adjustment.

Not so today, IMO.


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## Bret4207 (May 31, 2008)

TNHermit said:


> The hi /lo adjustment screws are smooth on the outside and they don't come off. If you want to adjust them feel free to buy a special screw driver . They run between 40-60.00. I sure wouldnt have wasted the time figuring out for a 4.00 screwdriver ,and a trip to town 13.00



What is this on? I've been wrenching on small engines for a long time and have yet to find a completely non adjustable carb. What make and model is this? All the Wlabros and Zamas I've played with are adjustable but have limiter caps.


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## farmrbrown (Jun 25, 2012)

I did the same thing not long ago on a chainsaw, only I used a common butt splice for electrical wires over the adjusting knob and turned it with a Phillips screwdriver.


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